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Basic technology guides with networking

Useful technology tips

Computers are arguably the most important item in your life. You can use them to search for information, apply for jobs, work, chat, shop, bank, read the news, catch up on TV programmes and much more.

Unfortunately though, computers can also give you cause for concern. They can give you health problems, money worries and even data loss disasters.

Yes, you may find your computer useful, but just like your car, it needs looking after, regular servicing and new parts to keep it running well.

Without such maintenance, your computer will likely: slow down and show strange error messages, get choked up with unused files and software and get infected with nasty software. And you will likely have to: take it somewhere to get it fixed and spend a small fortune.

This web page seeks to offer technology advice and help you manage your computer and stay productive in the digital age, which is also an increasingly mobile age.

Staying home, embracing virtual work along with e-learning leveraging digital technologies is safer not to mention low carbon low in emissions also - the Scottish government made clear that since 2017 its intentions have been to train young children in digital technologies computer coding in particular teachers too. Simple language and clear IT advice for computers, mobiles and tablets suitable for teachers and children is available from Scottish charity Computers and Integration.

This website contains a great many links to over 50 or fifty great personal online services that you likely use every day also many great useful charities featured or linked to on the Links page.

Digital online course materials enable slow learners to pause, take a breath, learn at their own pace this directly enables the most vulnerable with complex needs to really make a life from themselves, do better, make progress. Clear communication, breaking complex topics down into simple language really helps children in particular especially when simple language is used - very young children often progress with language, comprehension and understanding.

Contents - universal also unisex technology skills education for Scottish Smart Cities and the Scottish government since 2017 wanted early years teachers to learn computer coding

Antennas and The Fresnel Zone - Fresnel is an area around the visual line-of-sight of a sender or receiver of data like the visible horizon off an axis that radio waves spread out into after they leave the antenna like in a long wave and wireless signals can have a far field through the atmosphere - also there are multiple different types of antennas which emit signals in different directions, with different considerations for placement, signal intensity and range in some cases or instances

The Fresnel Zone (pronounced frenel) is the area around the visual line-of-sight like the visible horizon off an axis that radio waves spread out into after they leave the antenna like in a long wave and wireless signals can have a far field through the atmosphere. Contrast a wireless signal going from the ground to outer space versus Near Field Communication which is like RFID chip in a bank debit card for Contactless payment in a shop, store or retail outlet.

The Fresnel area which is the visual line-of-sight around a transmitter must be clear or else signal strength will weaken.

The Fresnel Zone is an area of particular concern for 2.4 GHz wireless systems - the other spectrum area is 5Ghz - for a period mobile phone use was banned at hospital sites due to mobile signals interfering with medical equipment. Certain equipment can share frequency bands.

Simultaneous dual-band routers are capable of receiving and transmitting on both 2.4 GHz and 5 GHz frequencies at the same time. This provides two independent and dedicated networks which allows more flexibility and bandwidth. Routers and network adaptors can operate on different channels - pick a wireless channel for your computer or network interface card and be careful in order to avoid interference for example as a rule of thumb or best practice pick channel one 1, 6 six or 11 eleven for close by devices to avoid signal interference - network monitoring software can help to limit or avoid interference but some people may use such software to sniff data packets and steal or misappropriate data there are good intentions versus bad intentions when it comes to using digital technology.

Although 2.4 GHz signals pass rather well through walls, they have problems passing through trees - with 5G there is a need for mobile masts every 1000ft so more masts more often can limit signal loss from environmental factors.

The main difference is the water content in each, walls are very dry, but trees contain high levels of moisture.

Radio waves in the 2.4 GHz band are absorbed easily by water. Absorption is how a sponge works to soak up water and when floods happen sand bags often used - the opposite is drainage and Surface Drainage removes excess water from the land's surface through channels or ditches. There are also Subsurface Drainage Systems, Slope Drainage Systems and Downspouts and Gutter Systems - most homes have a gutter and home owners usually need to clear gutters from time to time. Gutters can collect water when it rains but also they can get blocked - fill up and also birds can nest in rooftops and gutters can collect leaves from trees.

Subsurface drainage systems used often out in the countryside fields and are commonly used in areas where soil will not drain quickly on its own. Many agricultural fields require such systems to prevent crop flooding and allow work to continue.

With Radio waves in the 2.4 GHz band are absorbed easily by water, this is why microwave ovens (which also use the 2.4GHz band) cook food. Microwaves and intense heat can evaporate water. Water absorbs the waves, and heat from the energy cooks the food.

It is important to take the Fresnel effect, which is the area around a transmitter affecting line of sight, into consideration when designing a wireless network.

Line of sight between antennas may not be in a straight line so wireless signals may bend actually, get lost, attenuate, weaken or disappear altogether into an abyss, but the ellipse is produced in the Fresnel Zone.

Accurate antenna alignment can be aided by:

Using a balloon to establish height - helium balloons drift away up into the atmosphere when let go off and rockets use liquid nitrogen as fuel linked also to helium.

Binoculars or telescope - telescope look into other galaxies into outer space like Hubble and the successor the James Webb telescope launched around Christmas Day 2021.

Global Positioning System (GPS) is based on multiple satellites relaying signals which are messages carrying a data payload.

A strobe light at night - strobe lights can be linked to flares think a distress flare fired at sea by a vessel in distress. Flares also smoke signals - smoke can be visible for a long way think Iceland volcanic ash clouds in the past. Strobe lights, flares and smoke signals connected by virtual to antennas in a sense in principle since an antenna is about the transmission and reception of signals through the air a translucent medium. Translucent means allowing light, but not detailed shapes, to pass through; semi-transparent. Light-guided fibre optic signals use light it is a light-guided medium. Signals can be blocked by objects whether in a light-guided medium or over the air through wireless so really all signals in a data network are translucent. Wireless signals result in better data transfer for shorter range line of sight signals - data rates may slow down the further a mobile user is from an Access Point such as in a home when a user tries to connect to a router.

The curvature of the earth needs to be considered when a link is longer than 7 miles (11 kilometres) - Line of sight disappears at 16 miles (25 kilometres).

At long distances, the dish antenna like a microwave requires additional height to compensate for the bulge of the earth.

Attenas that may be used with access points discussed together with their signal direction, placement, signal intensity and range in some cases or instances.

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Electrics, dynamo, alternator and battery make up an electric car also electric vehicles are self-starting and Lithium Sulfur future batteries for EV vehicles - also Semi-Autonomous Braking uses sensors to predict a crash and apply brakes and EV vehicles may come with Blind spot monitoring, Lane Departure Warning System controls steering rack, Traffic Jam assist - acceleration, braking and stopping at speeds of 40Mph also Active Parking Assist is car parking itself also finding a car parking space and LiDAR is light detection and ranging

Electric cars and autonomous vehicles.

Argyll was the big motor name in Scotland early 20th century. The Alvis Leonides was an air-cooled nine-cylinder radial aero engine first developed by the British Alvis Car and Engineering Company. Alvis starting during 1948 flew helicopters like the Westland WS-51 Dragonfly helicopters, a reliable engine capable of operating in all climates but Britain moved to gas powered turbine engines.

Kintore lost its passenger services for the railway to Alford in 1951 and its main line closure came in December 1965 but Kintore station recently revamped carrying passengers once again on the railway. Kemnay railway station first built during 1901 the Victorian era and Monarch Queen Victoria died that year also during the 1930s and 1940s coal powered the trains running through Kemnay. Also first bus between Kemnay and Alford started around the 1980s.

BP offer mobility services via their Whim App - this will give city wide wide mobility choices with instant ticketing and pricing. BP combined with StoreDot during 2019 to develop fast charging EV batteries.

First American electric car made by the General Electric Automobile Company of Philadelphia using light lead acid batteries - 1898 and 1899 were the years of production and in 1898 Marconi sent the first wireless signal from Ballycastle to Rathlin island in Northern Ireland.

E-Volt electric car charges require a 400 volt Alternating Current Supply this is what comes from an electric outlet of sufficient capacity. Three charging sockets in use by electric vehicles - they are 2 x direct current sockets defined Chademo and CCS or Combined Charging System. They both provide 500 volts at 50 fifty kilowatts. Other socket type 2 two charging plug and gives off 400 volts Alternating Current at 43 kilowatts. Higher capacity car batteries take longer to charge but higher capacity batteries will likely lead to more distance travelled without having to recharge. Nissan Leaf 30 minute charge time using the Chademo plug for a fast rapid quick charge like 80 percent but still around an hour for a full charge.

2017 - next or second generation Nissan Leaf released or went on the market. First Nissan Leaf came to the market in 2010. 2017 model 40 kilowatt hour kWh battery and 147hp or horsepower with 110 kilowatt motor and an average range of 150 miles so from Aberdeen to Glasgow. ProPilot driving assistance degree of autonomy or autonomous driving.

2019 Nissan Leaf 60 kWh battery and average range of over 200 miles.

Typical electric vehicle 400 volt battery pack contains 192 cells of air-cooled, lithium manganese oxide batteries with options for 24 and 30 kwh units available.

Energy density might come from Lithium Oxygen or Lithium Sulfur. The latter offers 470 Wh/kg as a step change in a pouch cell already developed by OXIS Energy with a target output of 600 Wh/kg.

Audi, Volvo and BMW plan to relase a range of plug-in Electric Vehicles by 2025 - in America plug-in Tesla Model S has already been replaced by Mercedes, BMW and Audi to become the top selling brand, so that might be why Elon Musk recently sold his stake in Tesla.

1985 saw the bypass dual-carriageway open around Stonehaven - Spurryhillock road depot is at Stonehaven also a roundabout or junction where the A90 Aberdeen bypass joins with the A92 coast road and also enters the seaside town of Stonehaven. From Stonehaven, direct road links to Banchory also.

1935 the three wheeler Reliant Robin first appeared on British roads - in 1962 the Regal for vans was introduced recall Trotters independent traders and Only Fools and Horses with David Jason and also Buster Merryfield. Sheriffmill Garage in Elgin sold Reliant Robins. Older vehicles actually were more limited in speed - speedometers were limited to 60Mph maximum in some cases and there was no range beyond this point. Think Smiths US 509.

The Grampian Transport Museum in Alford opened its electric exhibition in 2008 - if looking at vintage old cars is what you like to do, you can pay the museum a visit.

Definitions needed for motoring these days now and in the future

Electrics, dynamo, alternator and battery make up an electric car. Electric cars are self-starting likely this is when cars stop at traffic lights and the engine falls silent. EV vehicles have electric headlights, dipping from 1920 also sidelights and brake lights.

Dynamo can power lights like on a bike for example - power lights when users also maybe commuters peddle or turn the pedals. Dynamo can power lights by kinetic energy, which is energy that is created by movement or motion for example user generated motion. Kinetic energy is motion energy and can also power watches for example shake watches to keep them functioning like a shake of the wrist. Dynamo linked also in a nutshell to kinetic energy and energy based on motion.

Cyclists give hand signals, may wobble from side to side, but indicators on vehicles replaced hand signals, semaphore arms first then flashing orange lights - blinking orange lights is hazard warning flashers and often stranded broken down motorists put up a hazard warning triangle at the rear of the vehicle to alert other motorists and prevent a collision. Electric cars have windscreen wipers and electric fan demisting - nowadays most brand new cars have windscreen wipers that come on when rain droplets fall and are sensitive to rain. Electric vehicles come with hot water filled cabin heaters with electric fan and electric push button horn. Sounding the horn is to alert other road users to your presence.

ABS is anti-lock braking.

ACC is adaptive cruise control.

AI is artificial intelligence.

APP is smart phone application.

AV is autonomous vehicle may also be linked to a self-driving vehicle and also AntiVirus software.

CVO is Corporate Vehicle Observatory.

EV is electric vehicle.

LiDAR is light detection and ranging.

Sat Nav is satellite navigation which is multiple satellites in outer space that work together to give a driver co-ordinates or driving directions.

Parking assistance systems using multiple ultra sound sensors.

Semi-Autonomous Braking uses sensors to predict a crash and apply brakes first introduced in Volvo car during 2008.

Blind spot monitoring using sensors first introduced in Volvo car during 2008.

Lane Departure Warning System controls steering rack.

Traffic Jam assist - acceleration, braking and stopping at speeds of 40Mph.

Active Parking Assist is car parking itself also finding a car parking space.

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The 7 seven stages of the software development lifecycle explained also the stages are Analysis, Design, Implementation, Testing, Documentation, Evaluation and Maintenance also Running totals in the case of a supermarket can be linked to quantity of items or products also this can be linked to shopping baskets and the total amount of money displayed for goods, also running totals may involve counters that are first set or initialised to zero and loops of blocks of code may be used

  1. HTML ol organised list element with li list element produces a numbered ordered sequenced list in HTML web page code
  2. Analysis - seek to understand the problem, issues and talk to the client
  3. Design - the planning stages for a computer program
  4. Implementation - translating or converting plans into an algorithm actually which is a set of steps actually, a series of procedures that get coded using a specific computer programming language like Pascal, COBOL, Cee plus plus perhaps Python
  5. Testing think playing computer games some people do this play games for a living to test scenarios, find areas for improvement, weaknesses in computer code - running programs with test data also to check software performs as expected. Test data can check ranges for example, lead onto checking data for validity to ensure that what someone wishes to find out is more likely to be obtained for real - actually form field validation in respect of web forms and JavaScript on focus controls for form elements can prove useful here - the onFocus JavaScript event handler to put a cursor in a specific online form field.
  6. Documentation - user guides and technical guides can help users but actually writing up problems, issues, workarounds can educate others in teams share knowledge pass it around advance progress at a faster rate. Important to focus on solutions also targeted solutions and highlight what problems they solved.
  7. Evaluation - checks to make sure end products and finished compiled software applications meet user desires and client needs - the client the person who pays for software may not be the end user and issues that affect the end user may affect the clients bottom line also profit and profitability.
  8. Maintenance - this is central to computer code and maintenance represents the do it again iterative nature may also be called looping of writing computer code, going back to the design stage after writing code and testing in order to alter designs and change computer code. Loops can be typical of computer code to make the process of coding more efficient - think independent blocks of code being brought together. Loops can bring more order and control - alternative events may occur when loops are broken and this is typically signified by clauses of computer code in the else statement of if then else endif.

Iterative nature of software development lifecycle like do it again involves overlap in stages and each stage feeds into each other. Iteration or do it again means repetition in a sense like repeating going back to a previous stage to make changes and improvements like in a design stage of a computer program with the view to changing computer code.

Perhaps in practice computer programmers may change code without changing designs it is easy enough to get swept away coding, but actually without changing designs changes in computer code may be less noticed and less understood and this could cause problems later when errors crop up and there is a need to debug and test. Diagrams can tell a story very well combine pictures or charts with words, but step by step explanations can really help others understand.

Computer programs may require different hardware capabilities like memory capacity, buffer allocation, processing speed also buffers can be linked to memory and also there are input and output devices. Input output can be linked to interrupts - keystrokes can be captured actually by hackers think keystroke logging and usernames and passwords can be stolen.

Consider a basic algorithm for making pancakes.

The ingredients is the inputs to the recipe.

The method is the statements that describe the process of making pancakes - statements usually step by step broken down using stepwise refinement like 2.1, 2.2 and 2.3. Computer programs need to be logical describe how to solve a problem.

The result is the outputs of the recipe - this is what people expect to happen. Normally in a computer program output appears on a computer display, on your smartphone screen in the case of apps for mobiles.

A tried and tested receipe like an algorithm or set of instructions can be used time and time again to produce reliable results.

Computer programs may involve initialising counters to zero and also a counter may increment by one after a block of code this is a running total. A running total may be used with a block of code that works in a looping fashion and be linked to a shop or supermarket. Running totals in the case of a supermarket can be linked to quantity of items or products also this can be linked to shopping baskets and the total amount of money displayed for goods.

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It is absolutely 2022 and artifical intelligence first mooted as a concept in 1968 film called 2001 A Space Odyssey - heuristics which is the foundation for anti-virus software scanning and heuristics linked to probability also to statistics like hash algorithms or hash codes also heuristics are rules of thumb in a broad sense for making immediate judgments that can facilitate problem-solving and probability judgments also heuristics like traits of a virus used to spot rogue software patterns, detect malicious software or computer code with bad intentions

HAL 9000 is a fictional artificial intelligence character and the main antagonist in Arthur C. Clarke's Space Odyssey series.

First appearing in the 1968 film named, called or titled 2001: A Space Odyssey, HAL is the name for the Heuristically programmed ALgorithmic computer) and is link a sentinal or artificial general intelligence computer also a smart computer system that controls the systems of the Discovery One spacecraft and interacts with the ship's astronaut crew.

While part of HAL's computer hardware the physical devices humans or users touch or interact with is shown toward the end of the film, HAL like a computer bot is mostly depicted as a camera lens containing a red or yellow dot, with such units located throughout the ship.

HAL 9000 is voiced by Douglas Rain in the two feature film adaptations of the Space Odyssey series.

HAL speaks in a soft, calm voice and a conversational manner, in contrast to the crewmen, David Bowman and Frank Poole.

HAL used a human voice over so actually it was friendlier than some computer voices nowadays.

So, in a nutshell, artificial intelligence is not a new concept actually - it has been around for a long time and really emerged at the cinema in 1968.

HAL used heuristics which is the foundation for anti-virus software scanning - heuristics linked to probability also to statistics like hash algorithms or hash codes also heuristics are rules of thumb in a broad sense for making immediate judgments that can facilitate problem-solving and probability judgments.

Heuristics actually is the process really of matching virus code in an antivirus application and detecting viruses - heuristics like traits of a virus used to spot rogue software patterns, detect malicious software or computer code with bad intentions desgined to cause mayhem and wreck havoc.

Many synonyms are linked to words and terms in the English language - possible to draw connotations between different meanings within the field of computing and in separate fields - actually the study of linguistics is actually important to computing. Linguistics linked also to natural language processing is a broad sense.

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Configure EIGRP routing protocol on a Cisco router and in computing there are really four types of data types - there are integers, boolean true false states or Yes / No, real numbers and characters - operands are the four standard mathematical symbols for addition, subtraction, division and multiplication symbols. Multiplication symbol usually an asterisk also like a wildcard and sometimes represents any character also Running totals actually can increment by one for example for a small set of instructions like a procedure or peice of computer code which can be linked to a loop to bring control add up for supermarket checkouts

Router(config)# mode this is the general router configuration mode on a Cisco router - it is the user prompt in a terminal screen for a Telnet session accessed after the enable command is entered with a password.

The EIGRP routing protocol is linked to autonomous systems by way of an ID or identification or reference number - to enable the routing protocol the following command is entered:

router eigrp autonomous-system-id (this is actually a numerical number or integer like 109 for example. Significant to note in computing there are really four types of data types - there are integers, boolean true false states, real numbers and characters. In computer programs there are also expressions which may be strings of data.

Typical Expression - a combination of operators, constants and variables.

An expression may consist of one or more operands, and zero or more operators to produce a value for example a+b c s-1/7*f. Operands are special symbols maybe addition, subtraction, division and multiplication symbols. Multiplication symbol usually an asterisk also like a wildcard and sometimes represents any character.

A real number, in mathematics, is a quantity that can be expressed as an infinite decimal expansion for example with two decimal places - long winded numbers usually rounded to two decimal places. Exponential numbers usually reference the number 3 three and can be really long never ending, for example lots of 3s after a decimal point.

Autonomous system number that identifies the routes to the other EIGRP routers. It is also used to tag the routing information.

There are two types of data and data is not information - data is meaningless. Taking ownership of data enables human analysis and discussions to produce meaningful insights. Qualitative is like comments and strings and Quantitative data, which are further classified into four types of data: nominal, ordinal, discrete, and Continuous.

The Microsoft Access database has AutoNumber for automatically producing an ID for a field in a database - this really is like a running total useful for a computer program linked to a supermarket or small convenience store for example.

Running totals actually can increment by one for example for a small set of instructions like a procedure or peice of computer code which can be linked to a loop and a looping mechanism which can bring control and structure - this is like a construct actually, provides definition to data enables an ordered, sequenced flow of computer code instruction.

It is visual cues actually built-in to software applications that stimulate recall about how to educate others on how to build also use software applications, but also start writing and describing it forces people to explain also justify - through this process others can learn. Explaining opens up learning actually and writings provide a tangible means of recording information and instructional support.

Short Text, Long Text, Number and Long Number along with Date / Time, Currency and Yes / No that are the basic data types of Microsoft Access. Yes / No is like boolean states akin to True False.

Enhanced Interior Gateway Routing Protocol (EIGRP) is an advanced distance-vector routing protocol that is used on a computer network for automating routing decisions and configuration.

The EIGRP transport mechanism uses a mix of multicast and unicast packets, using reliable delivery when necessary.

Network address starting 224 is a multicast address.

A multicast address identifies a group of hosts sharing the same address. Multicast addresses are not assigned to a device, rather, a device proceeds to listen for and receive traffic destined to a multicast group that it has joined by some process. Multicasting uses the UDP data packet or datagram message protocol - UDP is the connectionless transport protocol for IP data packets.

224.0. 0.22 is a multicast address. Multicast is used for IP addresses that can be subscribed to. A multicast IP address can be subscribed to by multiple network interfaces and will be routed by routers in a special way. This way you can create an IP address with multiple recipients. Multicast is send from one computer or network host to many computers or recipients or receivers usually other computers with real human users.

A simple example of multicasting is sending an e-mail message to a mailing list. Teleconferencing and videoconferencing also use multicasting.

Multicast protocols such as UDP/IP and RTP/IP are used to broadcast data to any number of receiving devices.

Unlike unicast TCP data, if a packet is not received, there is no mechanism or attempt to verify that and resend the packet. Multicast is widely used for video and audio data.

Real-time Transport Protocol (RTP) is a network standard designed for transmitting audio or video data that is optimized for consistent delivery of live data. It is used in internet telephony, Voice over IP and video telecommunication.

This autonymous system number in an EIGRP network for Cisco router configuration in a console window or session is a 16-bit value between 1 and 65,535.

The value chosen must be the same for all routers within a given EIGRP routing domain.

65,535 is the number of hosts on any given class B network - class B networks typically used for private networks or for medium sized organisations. 65,535 network hosts or users in a given network segment in the class B network address segment. 254 hosts typically in a class C private network per network segment and likewise 16,277,214 hosts or users around 16 million in a network segment for a large Class A network.

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Computer program version numbers and stepwise refinement - The Linux command ./configure is often used in connection with building software executables or compiling from source code in the Linux world also there are useful commands make and make install

Maths may be useful for computer programmers - maths and logic go hand in hand, maths logic useful for writing sequential, ordered in series, procedural computer programming also with stepwise refinement this is where steps are broken down like 2.1, 2.2 and 2.3 - computer program versions and versioning work like this. Google Chrome Version number at present is 103.0.5060.134 (Official Build) (64-bit) - recall Internet Explorer 6 six was dominant for a long time as a web browser.

Procedural program code normally executed in sequence - this may also be referred to as parsing, but also source code can be compiled line by line through a process known as compiling in Linux with the view or aim to executing a software program. The Linux command ./configure is often used in connection with building software executables or compiling from source code in the Linux world also there are useful commands make and make install. Running an exeutable on Linux usually involves dot forward slash like ./

Certainly dot forward slash or ./ is used to execute software source code in the Linux world.

Building or compiling source code in the Linux world has a specific order or sequence of operations or operands of command sequence - ./configure is first then make command followed by make install command. The pre-determined sequence or order of events or command syntax is important.

Stepwise refinement is based or really stems from the iterative do it again process of software development. Do it again refers to the looping nature of the software development lifecycle - for example Testing or Debug may necessitate need to go back to design stage and make changes also to computer code for improved performance also for security enhancements or create new functional aspects in software program.

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Broadcast storms can overwhelm a computer network and ping commands can check if a router or computer server is alive or active but also ping can lead to ping floods overwhelming servers known as Denial of Service attacks knock online servers offline also Arp cache on Windows 10 arp minus a or arp -a reveals paths to the Internet on Windows 10, also arp -d can clear or flush a local cache to resolve issues from Command Prompt

Flooding and Broadcast are two routing algorithms used in computer networks today. Flooding sends all incoming packets through every outgoing edge. Broadcasting means every device in the network will receive a packet.

In the case of a ping flood or a denial of service attack, it can be harmful to the reliability of a computer network. Messages can become duplicated in the network further increasing the load on the network as well as requiring an increase in processing complexity to disregard duplicate messages.

ping commands can check if a router or computer server is alive or active but also ping can lead to ping floods overwhelming servers known as Denial of Service attacks knock online servers offline. There is always good and bad intentions with computer networks - hackers may use port scanning as pre-emptive to hacking so really firewalls are important to only allow data traffic through designate ports like windows or access holes to online services.

Broadcast storms - A broadcast or data storm is excessive transmission of broadcast traffic in a network. This happens when a broadcast across a network results in even more responses, and each response results in still more responses, in a snowball effect.

When the switch receives a broadcast frame, it sends it out to everyone connected to it. In flooding the switch sends the frame to all because it doesn't know how to reach the destination. In broadcasting the host that created the frame itself addressed the frame to everyone. ARP process uses flooding not broadcasting.

Broadcast storms can be caused by - Due to high processing demands during a broadcast storm, communication may fail between end stations in the broadcast domain. During a boardcast storm, constant changes to the MAC address table prevent a switch from accurately forwarding frames. MAC address tables are often highlighted using the arp command which shows routes or pathways to the Internet.

Mesh Topology Flooding Technique - In flooding, the same data is transmitted to all network nodes like computers connected to a network this can make information delivery efficient support efficient transmission of data. Hence, no routing logic is required here. Moreover, in flooding, the network is robust, and it is not interested to lose data, but it leads to unwanted load over the network.

Flooding in networks downside - It is wasteful if a single destination needs the packet, since it delivers the data packet to all nodes irrespective of the destination. The network may be clogged with unwanted and duplicate data packets. This may hamper delivery of other data packets.

A broadcast message is destined to all network devices. Broadcast routing can be done in two ways (algorithm): A router creates a data packet and then sends it to each host one by one. In this case, the router creates multiple copies of single data packet with different destination addresses.

ARP broadcasts a request packet to all the machines on the LAN and asks if any of the machines are using that particular IP address. When a machine recognizes the IP address as its own, it sends a reply so ARP can update the cache for future reference and proceed with the communication.

Explanation. The Reverse Address Resolution Protocol (RARP) is an obsolete computer networking protocol used by a client computer to request its Internet Protocol (IPv4) address from a computer network, when all it has available is its link layer or hardware address, such as a MAC address.

ARP is linked to updating routing tables and routing information in connection with routers on the backbone of the Internet - By extension, an ARP table is simply the method for storing the information discovered through ARP. It's used to record the discovered MAC and IP address pairs of devices connected to a network.

ARP discovers the MAC physical hardware address of a network adaptor or network interface card a circuitboard inside a computer - By extension, an ARP table is simply the method for storing the information discovered through ARP. It's used to record the discovered MAC and IP address pairs of devices connected to a network.

The arp minus a or -a command on Windows 10 from a command prompt reveals routes or pathways to the Internet. This is known as the ARP cache on a local Windows 10 computer. A cache of routes or entries is how data packets are forwarded most efficiently - well it is how local user machines running Windows 10 know how to handle information requests, for example a user request for a web page or to send an e-mail by the way of Microsoft Outlook or Windows Mail an application on Windows 10 version ten.

Arp minus d or arp -d flushes the ARP cache on a local computer or machine, zeroes it or wipes it clean. This can clear issues linked to name resolution in connection with a MAC address or a physical hardware network adaptor but also there is ipconfig/flushdns which clears the local resolver cache.

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Breakdown of how satellite communications work with Network Control Protocol also DPUs really the purpose of NCP the network protocol is to connect two remote users located geographically independent of each other useful in adverse weather - shift from 3G circuit switched network to packet switching Internet TCP/iP communications with 4G and 5G - also Assembley language specific RISC instruction set used for device drivers also ARM chips used with mobiles and tablets, also Microsoft bundles lots of device drivers with Windows 10

NCP linked to parking also linked to Automatic Number Plate Recognition (ANPR) system, a different system entirely to the Network Control Protocol used in satellite communications. NCR for parking means that your vehicle registration number is captured when you drive in and out of a car parks using NCP. This allows for accurate determination of arrival and departure time in car parks.

The Network Control Protocol (NCP) is a mechanism used to establish and configure different Network Layer protocols for Point-to-Point Protocol (PPP) connections. The Network Control Protocol is used in satellite systems to relay messages also satellites are now being used for Internet access to really connect two remote users located geographically independent of each other this is what a Point-to-Point connection means in practice over the Internet normally by means of a TCP Transmission Control Protocol session.

TCP establishes sessions in communications at a data level that is why there is a three-way handshake with ACK data packets to say thanks. TCP sessions get established for the exchange of IP Internet Protocol data packets - these are the small units of information sent unordered across the Internet, packets less than 64Kbps known as runts and are malformed not proper data packets. ICMP is the error messaging protocol sends error messages and diagnostic information between routers usually these are small limited to essential information for resolving issues or problems and for fault finding may also be referred to troubleshooting.

Switches are also found in computer networks - they transfer frames. There is data encapsulation in a computer network where messages get wrapped in outer layers or encapsulated, framing is one technique and is done usually at the Data link layer the same layer where MAC Media Access Control addresses are involved these are the world unique hardware addresses physically shipping on circuitboards such as network adaptor cards. There is a protocol called Frame relay used also in connection with Cisco routers sometimes.

How Does Frame Relay Work? Frame relay uses packet switching technology. This means that it breaks data, such as call data, into smaller packets, also known as frames, to transmit it through a shared frame relay network. These data packets are then reassembled at the data's destination.

Frame really used in packet switched networks like the Internet - frame relay lower level encapsulation technology for IP Internet Protocol data packets with a message also called payload data - payload modules may go on rockets built using modular engineering by teams of people.

Traditional phone network hard wired in most homes using copper cabling is circuit-switched and 3G, 4G and 5G is known as cellular.

From circuit switching to packet switching a movement in telecommunications from 3G to 4G and 5G actually - In the cellular network GSM (2G) and UMTS (3G) use circuit switching for voice, circuit switched dialup (CSD) and short messaging service (SMS) traffic and use packet switching for GPRS data traffic. In LTE also 4G the entire network uses packet switching and has no capability for circuit switched network support.

4G vs. LTE. In laymans terms, the difference between 4G and LTE is that 4G is faster than LTE. The reason for this is that 4G meets the technical standards designated for it whereas LTE data transfer speed standard is merely a stop gap measure standard devised until actual 4G speed is realised.

The future of telecommunications is really packet-switched technology, but migration can take time - job roles here for telecoms engineers.

A DPU is a specialised piece of hardware and is used with the Network Control Protcol in satellite communications for the relay of messages between two remote users at ground level somewhere back on Earth - two users may be geographically independent of each other. So a DPU is special hardware in data communications and actually it is used in both satellite communications and also in data centres so a device with multiple practical applications in the real world.

A DPU also is essentially designed to process data moving around the data center. It focuses on data transfer, data reduction, data security and powering data analytics, as well as encryption and compression. This means it supports more efficient data storage and frees up the CPU the brain operation of a computer also known as the processor or microprocessor derived from silicon to focus on application processing.

A DPU is system on a chip (SoC) that combines three key elements: An industry-standard, high-performance, software programmable, multi-core CPU, typically based on the Arm architecture (a form of reduced instruction set like RISC from computing) and tightly coupled with the other SoC components.

ARM chips found in most mobiles and tablets from the Cambridge firm and also RISC is an instruction set linked to assembly level computer program code.

Assembly language really low level code close to binary programming - it is a special language really requires computer programmers with special knowledge of RISC (Reduced Instruction Set) computer program sets also assembly language - device drivers for computer hardware often tend to be written in low level assembly language.

Device drivers control the interface between computer hardware the physical devices and an operating system such as Windows 10.

From Windows 7 seven actually, Microsoft incroporated support for many device drivers - think Plug n' Play hardware detected automatically when connected to a computer.

Microsoft can be dominant with its Microsoft Windows software and Windows 10 is very popular certainly the software giant bundled Internet Explorer with Windows XP for example.

Really those with knowledge of special programming languages like Assembley language which really requires technical skill being close to binary can be overlooked in the computer industry by big major corporate giants who dominante the market.

Device drivers in Assembly language can be linked to Network Interface cards and nowadays there are SmartNICs increasing in popularity.

SmartNICs are different from regular NIC (Network Interface Cards) in two primary ways - capabilities and components. At a high-level, SmartNICs deliver accelerated, hardware-based networking, storage, and security capabilities for cloud, Artificial Intelligence, and traditional enterprise workloads.

In satellite message relay systems there is a Network Operations Centre likely at ground level - ground zero also linked to base stations think back to base camp and Infrared useful for night time communications also Infrared on television masts such as Durris - From a security perspective, the NOC functions as the first line of defense that enables the organization to monitor network security and recognize and address any attacks or disruptions to the network. Wireless signals from a base station radiate out to cordless phones in homes and a home can have multiple cordless phones linked to base stations loosely arranged in close proximity around a home. Nowadays mobile communications and Internet streaming also box set viewing very common in most households across the UK. Box set viewing can be linked with the couch potato lifestyle - sit back, relax watch TV passively this is also entertainment but also educational messages maybe attached.

In a business, network operations center (NOC) ensures that the business and the data are safe. The systems are operational and in order. It provides automated diagnostics and advanced alerts that help in keeping the business in operation.

Satellites higher capacity than on the ground radio waves like WiFi which use electromagnetic waves so much more data can be sent by satellite and via wireless than by cable also wireless communications more flexible but less secure also wireless more agile and natural disasters are increasing - to break it down first off, satellites use higher frequencies that are more powerful than other radio waves and allow them to concentrate all available power into a narrow beam. This helps to reduce bandwidth, which leaves more bandwidth over to send more communications.

Satellites also enable Earth monitoring and the monitoring of weather patterns also able to look down spot areas of trouble such as tree cover for example.

Satellites are GeoStationary placed 22,300 miles above the equator.

Breaking down satellite communications - GEO for radio broadcasting and VSAT for home computer users

GEO stands for Geostationary Earth Orbit. The communication satellites in this orbit operates at a distance of about 36000 km above the earth's surface and their orbital time period is about 24 hours. Geostationary Orbit Satellites are used for radio broadcasting.

Ground stations will have a satellite dish to link up or connect with satellites in the sky.

VSAT (Very Small Aperture Terminal) is a satellite communications system that serves home and business users. A VSAT end user needs a box that interfaces between the user's computer and an outside antenna with a transceiver. The tranceiver receives or sends a signal to a satellite transponder in the sky.

VSAT great potential application the London and New York Stock Exchanges - A very small aperture terminal (VSAT) is a data transmission technology used for many types of data management and in high-frequency trading. VSAT can be used in place of a large physical network as it bounces the signal from satellites instead of being transported through physical means like an ethernet connection.

VSATs access satellites in geosynchronous orbit or geostationary orbit to relay data from small remote Earth stations (terminals) to other terminals (in mesh topology) or master Earth station hubs (in star topology).

Economic recovery for the global financial system needs to be quick and responsive to shocks and natural phenemena - VSAT services are independant of other wired and wireless mediums used as transmission network service provider. Hence it is a great backup system which is available during disaster and emergency situations.

Satellite boosts content availability in the face of freak weather events, natural phenomena events.

2017 published by IEEE originally ICN-based protocol architectures for next-generation backhauling over satellite - https://ieeexplore.ieee.org/abstract/document/7996549

Abstract of published work or blurb in a nutshell - The increasing demand for mobile services has been calling for new anywhere-anytime communication paradigms, building on the integration of heterogeneous technologies, such as satellite, LTE, and the new generation of mobile networks, i.e., 5G. In particular, the network design philosophy has shifted towards a more content-oriented approach so as to more efficiently meet the users' demands in terms of fast content availability and service continuity. Following this line, this paper proposes an enhancement to the PURSUIT information centric network (ICN) architecture, so as to improve the quality of experience of users in highly mobile environments. Simulation campaigns show the performance gain offered by the proposed solution with respect to regular PURSUIT implementations and benchmark IP-based strategies.

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Unicast, Multicast, Broadcast and Anycast - the latter useful for sending to a computer in a group or cluster and computer servers can be clustered together for redundancy fault tolerance as well as multiple hard drives being bound together to mirror data held in racks in server farms - Fault tolerance is actually created from multiple server computers bound together in a cluster - when one server fails, a replica server computer is able to continue to provide service and replica servers are the hallmark of the Internet

Ability to keep personal information secure and use online storage solutions for example is really key to digital security while having the capability to transmit small updates in information across a computer network with minimum personal data stored on personal devices. Heavy lifting with computer processing power can happen in the cloud with computer servers usually built with more powerful processors and also multiple processors like 32 processers in a typical server computer in a server farm. Windows 2000 actually supported 16 processors per server computer - that was the past around 20 years ago but nowadays desktop personal computers from Mesh Computers for example may come with massive amounts of memery also multiple processors built into a computer known as cores - dul core two processors working together in tandem, quad core is four processors really quadcore more synonymous with Quantum computing but not exactly - Quantum computing involves fast computer processers, many calculations per second and high power number crunching to predict weather and climate patterns. Scientists been using high powered machines for a while and that is how they have actually predicted more intense weather patterns - they have long been warning about it.

Websites and publishing can work well to inform and educate - information on public display via a web-based platform is readily accessible from anywhere enabling right-click on a web page, clicking View source to see also save web page code. Clean code and taking the time to write in HTML the raw native language of the web may preserve information better long-term and CSS or the style sheet language can present web pages for social inclusion large print for better display on mobile devices potentially to reach more people including African children, although still an issue around web hosting firms, public computer servers also mirroring data in server farms with customer also personal data stored likely in a RAID5 configuration - different levels of RAID actually with different levels of redundancy built in, there is RAID 1-5 or five levels actually. RAID is for Redundant Array of Independent Hard Drives or perhaps Inexpensive Disks - small capacity hard drives are more cost effective so this is the benefit of mirroring also, really mirroring also enables cost savings for storage and back-up firms also cloud hosting storage providers. Everyone and individuals may have different points of view - really explaining points of view, breaking complex topics down and writing, talking about issues surrounding a topic is really how to advance education.

Internet Control Message Protocol ICMP for sharing error messages usually just essential information between backbone Cisco routers on the Internet.

Important to mention broadcasting in computer networks - for more information, see https://en.wikipedia.org/wiki/Broadcasting_(networking). Professionals in computing may devote hours to updating Wikipedia - the online encyclopaedia that actually does contain a treasure trove of useful technical information. Sharing techical information online actually is what teaches others because complex technical information can be easily forgotten and there is also a learning curve in the first place - many Cisco academies exist for the training of the Internet generation to maintain the Internet ecosystem and network of routers and switches.

Broadcasting refers to Unicast sending to a single computer on a network specifying a destination or receiver, Broadcast sending to all computers, Multicast sending to multiple computers, multicast enables recipients or receivers to be chosen so perhaps this is more useful than broadcast and Anycast. Anycast actually harder to understand in concept - a computer sending an Anycast message sends a message to one computer out of a group or cluster of computers, clustering of servers is an expression in computer networks. Anycast normally used to send data packets to a computer in a cluster and anycast tends to be used to send to the nearest computer in a group. RIP routing protocol along with RIP version 2 two actually uses a simple metric of hop count to count how many routers in a path between two end points. Hop counts and metric used with Anycast to determine the closest server computer in a cluster.

Broadcasting actually in data communications can be more efficient - telling everyone and a catch all can enable one message to be flooded across a network making Internet communications more efficient. Catch alls linked also to wildcard masks or like asterisks or stars in Cisco Access Control Lists for security on Cisco routers. Access Control Lists configured on Cisco routers can using software or a set of pre-determined rules filter data packets, or datagrams, also messages provide filter and greater security on independent networks which are segmented by routers - muliple routers and switches linked or connected together make up the Internet. There is an expression known as daisy chaining.

The daisy-chaining method of creating priority includes a serial connection of all devices that request an interrupt. The device with the highest priority is located in the first position, followed by lower-priority devices up to the device with the lowest priority, which is situated last in the chain.

Daisy chaining also occurs or happens in connection with electrical sockets or electrical outlets. Electricity is actually the future like EV electric vehicles.

Technically, you can have as many outlets on a 15 amp circuit breaker as you want. However, a good rule of thumb is 1 one outlet per 1.5 amps, up to 80 percent of the capacity of the circuit breaker. Therefore, we would suggest a maximum of 8 eight outlets for a 15 fifteen amp circuit.

The National Electric Code has no rules regarding how many outlets you can daisy chain off a single breaker. But generally speaking, it's best to keep the number below 13 because of average current draw.

For more information on electrical standards, refer to the Institute of Electrical and Electronic Engineers who define or make standards really this is the official standards body and electrical signals are used in computer networks - https://www.ieee.org/.

In a nutshell, Unicast, Multicast, Broadcast and Anycast - the latter useful for sending to a computer in a group or cluster and computer servers can be clustered together for redundancy fault tolerance as well as multiple hard drives being bound together to mirror data held in racks in server farms.

Fault tolerance is actually created from multiple server computers bound together in a cluster - when one server fails, a replica server computer is able to continue to provide service.

Replica servers are also the hallmark of the Internet and actually replica servers are really obvious in the Domain Name System or DNS or name servers. DNS servers referenced on home computers in ipconfig/all in Command Prompt Windows 10 ten - default gateways also mentioned and they are home routers and a portal or window also an Access Point to the Internet. Wired also Wireless home routers are Access Points in an Infrastructure Network or an Infrastructure Service Set network and each router has a unique Service Set Identifier. Ad hoc networks used with two digital devices send messages without the support of a router also known as an Access Point.

DNS provides name resolution services domain name to IP address machine address mappings. DNS helps everyone to remember a friendly domain name - most people would likely struggle to remember an IP address, an often four digit code separated by dots, for their favourite website. IP version 4 was becoming exhausted in supply of addresess so IP version 6 six addresses were created - these are much longer 128-bit hexadecimeal numbers built on a base of 16 from the 16 times table. The base 16 number system or the 16 times table is really the basis for Maths is STEM Science Technology Engineering and Maths as is floating point representation, boolean states true false, zero and one as well as technology gates such as AND, OR, NOT and NAND. Technology gates also refer to boolean and the NAND gate linked to NAND memory the type of memory that actually holds memory information without power.

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Border Gateway Protcol is a routing protocol for independent or autonomous routers to exchange topology information - three main routing protocols used on the Internet are distance vector, link state and path vector. OSPF is a link state routing protocol that calculates best path most efficient route for data transmission and OSPF updates exchange topology information with nearest neighbours

Border Gateway Protocol can be configured on Cisco routers, which are the backbone of the Internet - also Open Shortest Path First or OSPF is another routing protocol, the best path protocol for sharing topology information in the most efficient manner.

BGP Border Gateway Protocol is a distance vector routing protocol. It really enables the exchange of routing information - topology information for the networks associated with a router - between independent systems also known as autonomous systems.

Routers talk to one another - routing protocols enable the machine to machine communication or exchange of management data packets for a network.

Distance vector routing algorithm simplifies the routing process by assuming the cost of every link is one unit. This means or translates to the efficiency of transmission being measured by the number of links to reach the destination.

In Distance vector routing, the cost is based on hop count. Hops refers to routers linked or interlinked in a chain also a network - routers generally connect to one another filter or forward data packets onto a destination computer as well as send neighbouring routers management information on the connected networks - this is topology information often sent using routing protocols think RIP Routing Information Protocol the basic one also RIP version 2, BGP also EIGRP, IGRP and OSPF. These are all the main routing protocols that are in existance and used with Cisco routers on the backbone of the Internet, a network of networks.

From the Router(config)# interface screen, type in router bgp 120 to enable the Border Gateway Protocol for autonomous system 120.

Again from the Router(config)# interface screen, type in network 192.168.1.0 where the numeric dots represent the IP address of a network - change as appropriate.

The show ip route command displays all available routes or paths in a router also the networks a specific router knows about or has learnt about. Neighbouring routers in a heterogenous Internetwork learn about other networks with the aid of small, efficient management updates or information exchanges using routing protocols.

When a data packet comes in on a network link, the router reads the network address information in the packet header to determine the ultimate destination. Then, using information in its routing table or routing policy, it directs the packet to the next network on its journey.

Data packets are sent unordered across a network - reassembly of data packets in a split message is possible by a router reading header information in a data packet, basically each packet have flags in the header information, the real message is known as payload data.

Three main types of routing protocols used on the Internet - distance vector, link state and path vector. OSPF is a link state routing protocol - topology information for linked networks exchanged with nearest neighbours.

OSPF (Open Shortest Path First) routing protocol enables complete knowledge of a network topology - all neighbouring routers can calculate best path through the network - the optimum path, the most efficient path for data transmission.

show ip ospf command displays status information of running OSPF processes.

OSPF link state best path routing updates a flooded throughout a network, so all neighbouring routers becoming aware of all networks connected to the routers involved in the exchange of management router updates.

OSPF does not use TCP or UDP transport protcols, so the OSPF routing protocol reproduces or replicates data in every data packet transmitting much redundant information. OSPF is a routing protocol with significant overhead in respect of management updates conveying topology information for connected or linked networks to a router and neighbouring routers.

From Router(config)# mode, type in router ospf 1 to enable ospf routing protocol.

From Router(config-router)# mode, type in network 192.168.1.0 255.255.255.0 area 0 - change for your own IP address and subnet mask for the network you are trying to configure for use with the router.

The area part of the command above is just a means to classify networks into a given area or cluster in a sense.

In a path vector protocol, a router does not just receive the distance vector for a particular destination from its nearest neighbor. Instead, a network router receives the distance as well as path information.

Distance is known as a metric in a network - the other main or major metrics include jitter, packet loss, throughput, packet reordering and quality of service. Packet reordering really symbolic of the fact data packets are often small with header or control information with addressing information and payload or message data - also packets sent and received in unordered data packets, packets sent in segments.

Jitter - The lower the speed of the connection the higher the latency or network delay. The more people using a connection, the greater the degree of jitter - more users equals more congestion so jitter really indicates a delay in data transmission.

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The RIP routing protocol or set of rules that enables an individual router to learn about neighbouring routers, other networks and paths through an Internetwork - also RIP enables a router to tell other routers and share information about its connected networks

The router rip command is entered in the general Router(config) mode of a Cisco router - this command begins the RIP router process. The no router rip disables the RIP routing protocol. RIP is a routing protocol and the set of rules that describe how routers exange information with due regard to the networks each router links to. The RIP routing protocol is used to help connected routers in a network learn about other networks. In a nutshell, the RIP router process is a network learning process for connected networks within the same logical area or group also clustering of an Internetwork.

When the router rip command is entered it enables the RIP router process, a basic routing protocol with a metric of hop count. Hops measure all the routers in an Internetnetwork - in essence one router is a certain number of hops from a distant router. Hops is just a way to count all routers in a network or over a backbone link. The tracert command in Windows 10 version ten Command Prompt can be used to trace points of failure in a network isolate routers causing problems or connectivity issues alongside the ping command to test the responsiveness of each router (type in cmd in a Windows 10 search box to access Command Prompt).

From the Router(config-router)# screen (the RIP mode), the networks linked to a given router (the router being configured) are thus entered from the RIP router configuration mode.

From Router(config-router), type in network network-address so something like network 192.168.1.0. The network command is used to add all networks connected to a specific router to its routing table. A routing table on a given router is really a map of all networks or all learned routers a router knows about. Each router is aware of local networks directly connected and local routes to other routers out of its interface ports.

show ip route command shows a router's routing table - lists all directly connected networks as well as all paths or routes to other neighbouring routers. Really the show ip route command shows paths through an Internetnetwork from the perspective of an individual router - routers running the RIP routing protocol can learn new information from other routers about other networks that are alive and active are neighbours in a sense in a given area. Worth bearing in mind that the Internet is made up of multiple routers and switches - the Internet is vast.

Education on Cisco router configuration can broaden awareness about how the Internet works also how routers work at the high-speed backbone level. This can accelerate Internet development, encourage and inspire young minds to go into roles associated with router configuration and network design and management. Education must always come first to really lead the pace of change and Internet development.

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Add a password to a router also reset passwords - also Set a Cisco Internet backbone serial router interface using the ip routing command and also within that use the interface command to assign an IP address also a subnet mask to a router link, interface or port - also make an interface active come alive with command no interface shutdown - also add description text to a link to help others to understand

Cisco routers can be secured for admin access using a password using the command enable password followed by a password. This is a simple means to add a password to a Cisco backbone Internet router. All router admins will need this password to log into a particular router that has been password protected - important to circulate passwords among admin personnel responible for a router within a designated area. A group of people may be responsible for a collection of routers within a small segment of an Internetwork.

The enable secret command followed by the password set using enable password is used to enter the enable mode. enable password command sets a password for a Cisco router once and enable secret followed by the password enters enable mode - this enables a Cisco router for configuration, puts it in the global configuration state or the main state where all other commands are entered to configure a router.

The command no enable password removes a password from a router, but to remove a password when you do not know a password, there is a password recovery procedure to follow. Different router makes and models tend to have a different procedure with varying help offered.

The passwd admin command from the main root Router prompt when the router is switched on or powered on and after brief start-up instructions loaded from flash NVRAM memory enables a new password to be set. passwd admin followed by a new password sets a new password on a router. The passwd command can also be used on Linux systems to set or change a password for a user account.

Cisco routers have what is known as flash memory - NVRAM or Non-volatile RAM, memory that does not get erased when routers are powered down or disconnected.

Routers are configured via console ports connecting via Aux or Auxiallary ports via Telnet mode connections.

The ip routing command on a Cisco router from the main global configuration mode marked as Router(config) enables a router to perform its core function to route, switch, filter or forward data packets entering from one router interface or port and switching a data packet to the most appropriate port based on its destination address.

The interface command identifies serial interfaces or router ports for advanced configuration such as to set an IP address on a router interface or port. Router interface ports can be ethernet or serial, but usually when the interface command is used, the first ethernet port for a local network is set for configuration as interface ethernet 0.

Interfaces or ports the points that link to cables for example are identified as numerical numbers going up in increments - a router can have multiple interfaces since routers are like roundabouts, for example to configure a serial port or interface type in the command interface serial0 for the first serial ports.

Parameters can be added to the interface command to really configure a Cisco router - two options are point-to-point and multipoint. Most connections over the Internet actually are point-to-point - this signifies two end stations connecting and sending data through an Internetwork with multiple routers where the rules of operation are TCP/IP.

Point-to-point links usually use Point-to-Point Tunelling Protocol on the worldwide Internet to connect computers over a telecommunications network, a protocol is just a set of rules to control or govern data communication ensure the two or more computers that engage each other speak the same language.

From an interface configuration mode represented by Router(config-if), type in ip address followed by a numeric ip address and a subnet mask. For example, ip address 192.168.1.0 255.255.255.0. The subnet mask used in this example is for a private Class network with around 254 hosts or computer on the private network.

Usually assigning an IP address and a subnet mask to a router interface or port is standard - the command interface no shutdown brings an interface up, puts in an active state ready to send and receive data across a network of networks or the Internet.

Interface configuration mode represented by Router(config-if) - the standard router global configuration mode is represented by Router(config). Note the key discrete differences between router modes - it is important because depending what mode you are in, it affects the commands available for entering as part of router configuration.

Interface commands are different from global router configuration commands. In the main Router(config) or global configuration mode, the interface command changes the mode to Router(config-if). The command interface serial0 does specify serial interface 0 the first serial port as active for configuration or set up.

In the Router(config-if) or interface configuration mode for a particular interface, type in description and then a text string, logical text that identifies the purpose of a link. Adding meaningful text can really help others, other admins responsible for the same router in an Internetwork.

Within the Router(config-if) command mode for configuring an interface, type in for example bandwidth 1540. This sets the bandwidth for a link to 1.54 megabits per second. Link speeds can vary - much faster link speeds are in common use these days.

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Transmission Control Protocol basis for Internet data trasmission uses SYN for synchronisation to help make Internet communications more reliable with less errors and Cisco routers have a clock rate command - really teamwork vital within neighbouring areas of an Internetwork to make Internet communications more reliable with less errors

Cisco routers which are often the main link on the backbone on the Internet have a clock rate command to enable clock timings really to be set. Clocks might enable synchronisation of signals in Internet communications, but actually the clock rate on a Cisco router is not actually linked to time in a very really sense not the standard 24 hour clock we all know which is also linked to timezones.

Well clock rate might be linked to time since it helps to keep signals in sync or in synchronisation helping real-time systems to work normally in an optical state - keeping signal synchronisation actually is really important and vital for real-time systems where real-time information is relayed across the world by way of the Internet. Transmission Control Protocol has a SYN flag or bit - end to end connections by way of the Internet start off with a three-way handshake for reliable data communications.

SYN for synchronisation used also with ACK for saying thanks acknowledging a data transmission. The world now depends on the Internet and real-time information really fundamental for future hi-tech air travel - last year 2021 saw an all-electric plane deliver parcels to Scottish islands as announced by BBC News. It is really a test flight for electric aircraft.

The clock rate command setting in a Cisco router is useful for linking or connecting routers in a lab environment - useful to help students learn more about Cisco routers and computer networking.

Clock rate sets how many bits can be sent over a networked link in a given timeframe. If the clock rate is set to 64000, you will never be able to send faster then 64 kbs over the interface. The rate of modems actually was 56k - some users may still remember dial-up modems often they made a noise when dialling to the Internet. Broadband and ADSL modems was an advancement on traditional 56k modems which really started off Internet connectivity in most homes in Scotland.

The command show controller identifies the specific end of a cable plugged into a Cisco router - this might aid fault finding also troubleshooting help in the repair of cabled network links connecting to routers and also prevent user frustrations with network downtime also failues involves cables on the backbone of Internet the real high-speed fibre links where light signals penetrate or travel through the cables.

Use the clock rate (or clock rate) interface configuration command to configure the clock rate for the hardware connections on serial interfaces to an acceptable bit rate. Use the no form of this command (no clock rate) to remove the clock rate if you change the interface from a DCE to a DTE device.

A data circuit-terminating equipment (DCE) is a device that sits between the data terminal equipment (DTE) and a data transmission circuit. It is also called data communication equipment and data carrier equipment. Usually, the DTE device is the terminal (or computer), and the DCE is a Cisco router.

A transmission circuit is a network such as the Internet a packet-switched network.

DCE is a router terminator of a circuit (the device that filters Internet traffic, forwards data packets out the most appropriate interface or port onto network links choosing a link in the process) and DTE is a computer - computers are terminals (dumb terminals referred to Citrix for example really dumb as in light user activities with most processing on a server computer).

Using the no form of this command on a DCE interface such as a router sets the clock rate to the hardware-dependent default value. bps (bits per second) values are physical-layer dependent (for example RS232 or V.35).

Officially, RS-232 is defined as the Interface between data terminal equipment and data communications equipment using serial binary data exchange.

V.35 is an ITU International Telecommunications standard for high-speed synchronous data exchange. Asynchronous links on the Internet are actually more common where rates are variable - this actually is what leads to the occurance of more errors. This is what makes data transmission error prone and Cyclic Redundancy Checks enable error checking on file integrity for example after file download.

Asynchronous Transfer Mode is an important WAN or Wide Area Network technology that involves or makes use of frame encapsulation. Data packets get encapsulated in frames at the lower levels of the 7-level Open System Interconnection model often used in computer networking to help others understand teach computer networking principles. Education is usually at the forefront of technological advancements.

Asynchronous Transfer Mode is used with time division multiplexing - fast fibre optic networks with light-guided signals use wavelength division multiplexing. Being able to fine tune wavelengths actually has advantages with due regard to data integrity and high fidelity signals. There is a trade-off actually fast fibre networks enable ability to send data again persist versus errors in data.

Really understanding clock synchronisation is at the heart of making data sent and received by way of the Internet more reliable, better data integrity with less errors. The Cisco clock rate command and keeping clock rates the same across logical parts of an Internetwork is fundamental to improving data reliability with less errors - really co-operation and teamwork is really important.

Clock rate measured in bits per second or bps - the bit is the most basic unit using in computing on computer networks represented by two binary states zero and one.

Clock rates can be set on a Cisco router using the following values - 1200, 2400, 4800, 9600, 19200, 38400, 56000, 64000, 72000, 125000, 148000, 500000, 800000, 1000000, 1300000, 2000000, and 4000000.

Higher clock rates obviously result in more bits per second being sent in a smaller time frame - data packets usually unordered when sent and received with header information in the actually data packet as well as payload data the actual message sent across a network, need for reassembly making higher bit rates uncessary in practical reality.

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Important to be able to check on router the default gateway status and detect when links are down, fix cables, troubleshoot, replace failed routers - wireless signals can involve greater signal attenuation or more delays - real-time systems such as the banking network involve real-time changes to financial information so clock timings being in sync fundamental

Cisco big tech company makes routers for the backbone of the Internet.

Main mode for router configuration is known as the global configuration mode.

show ip interface followed by an interface could be represented by int0, int1 for example so command is show ip interface int0.

show ip interface useful to check on the status of a router's interface from Cisco's global configuration mode - when the link is up, working and active or whether the link is down and not working. Link failures can be caused by broken cables need for cable testers also finding cable faults difficult and repairing cables more difficult than wireless a real physical demanding job - failure of routers on the backbone more likely when computers are connected by wireless means - routers main connection devices no cables linking routers to wireless connected computers, but computers connected via wireless have wireless network adaptors either PCI / PCI Express which can fail with a unique the world over MAC (Media Access Control) address linked to a computer's motherboard or as wireless USB dongles. PCI slots bigger and white - PCI Express really smaller slots more representative of embedded computing as part of modern desktop computers.

Wireless connected computers usually slower to access the Internet than wired computers and with this signal attenuation is greater over wireless links hence the delays NASA engineers really experience when communicating with rovers on far away worlds such as Mars.

Links and networks can and do fail also go down but then there is downdetector.com to monitor the status of downtime affecting mobile phone networks.

Web monitoring also alerts is really useful - network administrators really being alerted to network issues in a timely manner is actually important to keeping users happy, productive also and also this is also fundamental to business profits and ongoing success in business for telecom and broadband provider firms also same applies to mobile networks such as Three, Everything Everywhere and O2.

Cisco router interfaces can have a status of Ethernet usually eth0 for short, but also null (or no active link), serial, token ring and so forth. Cisco router interfaces normally serial but aux or auxiallry links are used for telnet connections and for remote control or log-in to routers for admin purposes.

Cisco routers usually found in enterprises on the backbone of the Internet - young people though do usually learn at home in an Infrastructure mode network with a home router as an Access Point, which is also the central point in a network that links computers together shares an Internet connection.

The sole purpose or the primary also fundamental purpose of a network actually is to share resources - such as an Internet or Net connection, also print devices (Apple Air printers actually enable printing over WiFi from iPhones and iPads). This is wireless printing.

Files can be shared between computers - networks enable back-up of files from computer to computer easier and Linux back-ups were usually scheduled as cron jobs - Windows 10 version ten forms a HomeGroup for a network of computers and there is an option for usernames and passwords this is authenticated access to resources based on priviledge. Confidential information is usually secured with usernames and passwords such as medical information.

Significant to note also the default gateway line represented by ipconfig/all in Windows 10 command prompt launched or opened by cmd command in Windows 10 search box gives the IP address of a router, even a home router. The address of a local router for a home network is usually an IP version 4 four address, not the 128-bit IP version 6 long winded IP number. Type in http://192.168.1.254 or the IP address that represents the default gateway in ipconfig/all to access the router admin interface for a typical home or office router. The IP address maybe http://192.168.1.1 and also the exact number can vary - it may also be http://192.168.2.1 but the main point is the default gateway line in the command ipconfig/all sheds more light pinpoints or tells the exact specific address.

Cron is a job scheduling utility present in Unix like systems. The crond daemon enables cron functionality and runs in background. The cron reads the crontab (cron tables) for running predefined scripts. By using a specific syntax, you can configure a cron job to schedule scripts or other commands to run automatically.

Shedule a cron job - this uses a script to automate back-ups of data, often it is more efficient to do back-ups during the night when minimal server activity is taking place. System maintainance of banking services such as that used by RBS the Royal Bank of Scotland is done in the early hours of the morning - if you try and log-in to mobile or digital banking at the time, you will likely be unable to due to system maintenance. System maintenance for banking systems can be automated however - banking systems are known as real-time computing systems where information, really key financial information, changes in real-time or very quickly. There is a need for clock timing synchronisation between multiple Automated Teller Machines for example and the network of ATMs is vast at present.

Daemons are usually responsible for services in the Linux world for example computer server services - a server provides services to a user, online services in an Internet connected world. The httpd daemon is used for a web server such as the popular Apache web server - Apache really is the most popular web server on the Internet, more popular than Microsoft's Internet Information Services.

Linux daemons absolutely no relation whatsoever to Daemon Internet, a company that provided Internet services in the UK - the company actually has gone by the wayside. Companies can go bust and actually the technology industry is highly competitive. The fierce competitive nature drives on improvements in services for the user, but young people do need to keep a digital skills portfolio so their skills development is tracked long term and fosters ongoing continuous improvement as well as career progression.

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Cisco routers have serial interfaces or ports and Cisco routers control the flow of information on the high-speed Internet backbone - routers reference routing tables for default route information, key information which enables a router to know what interface to put or send a data packet out by default - also multiple routers used in the default route command provides fail safe redundant options

Routers contain routing tables which really contain navigation information - incoming data packets to a rounter interface or port get checked against rules in a routing table. Routing tables can contain network information about what to do with a data packet that arrives, and in particular where to send it to - in other words, which router port a data packet should be switched to also referred to as traffic filtering in data communications.

In computer networking, the default route is a configuration of the Internet Protocol (IP) that establishes a forwarding rule for data packets, the unit of information for a message sent over the Internet, when no specific address of a next-hop host is available from the routing table or other routing mechanisms.

The default route is a route that a router uses to forward an incoming packet when no other route is available for that packet in the routing table. Routers use the routing table to make a forwarding decision, decide what to do with a data packet and select the most appropriate router port and network link - routers can have multiple ports and some network links can have a higher bandwidth. Router ports are usually known as serial links usually called int0 or int1 to denote the names interface0 also interface1, the names of interfaces router ports with numerical differences, changes or states.

The default-route is used on Cisco routers, while the default gateway is used on hosts - a default gateway is typically the address of a home router, a gateway is an Access Point or AP to the Internet in a Infrastructure network, ad hoc networks have definitely no Access Point, there are more security issues and devices talking to one another are independent.

Access Points also home routers can function with Network Address Translation where a private network and multiple computers, hosts or network nodes link or connect to the Internet via a single publicly accessible IP address.

Use of NAT and PAT really do cut down on wasting publicly accessible IP addresses, the numerical addresses that all computers on the Internet are assigned. PAT uses port numbers and a single IP address, different ports used for a different Internet service on a computer.

A home router typically has a firewall built-in - this is a hardware firewall but computers can also install software firewalls, these are software applications.

As an example, consider a simple home router that connects your home network to the Internet. This router will have two routing rules - one for computers on your internal network, and a default route.

Router ports or interfaces can function at different speeds or rates - this affects data transmission and also data throughput, the amount of data that can be transferred through a router interface in a certain period of time.

Internet Protocol data packets or datagrams are sent unordered in segments not in sequential order (the Internet messaging service IP is chaotic really and in practical reality, routers help to provide an ordered flow of information filtering data traffic on the high-speed Internet backbone in the case of Cisco routers) - so a message must be reassembled when multiple data packets reach their destination.

Data packets sent in unordered all jumbled up segments, reordering of data packets in a standard message for example an e-mail is a complete message happens by routers referencing header information in a data packet - this is control information with also address information such as source and destination also message flags as well including control bits binary state information, payload data is the message that gets sent and received passes through a router in transit.

On a Cisco router, type in default-router and then hit Enter to go into dhcp-config mode. DHCP is Dynamic Host Configuration Protcol - DHCP is a service that automatically assigns IP addresses to computers on a network, this is a service all home routers normally do and this role is transparent to most home users. DHCP automatic assignment of IP addresses to client computers on a home network happens has background process oblivious to the average home user.

From the dhcp-config Cisco router mode, the following command line namely - default-router 192.168.0.1 192.168.0.2

The line above sets two routers which are set as the default route - basically a default route represents a router where data packets are sent or forwarded to.

Setting multiple routers using IP addresses actually provides redundancy since just having one router address may cause one problem if a router is available or is suffering downtime. Redundant routers and switches is a really important fail safe concept on the backbone of the Internet - the real high-speed links, the often total fibre optic links with the light-guided signals.

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Introduction: a brief history of networking

In the US during the 1950’s, DARPA (Defence of Advanced Research Projects Agency) had a desire for computers in different locations throughout the country to be able to communicate with each other, and at any time.

This desire led to the creation of the first computer network. This experimental network of computers led to the development of scientific and educational networks within the US.

It was later discovered that people were using these networks to exchange gossip and generally to chat with other people in different locations. This finding is one of the factors, which has contributed to the rapid development of many Wide Area Networks, and indeed the Internet, which is merely one large Wide Area Network.

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Types and Characteristics of WANs

A Wide Area Network, otherwise known as a WAN, consists of two or more Local Area Networks (LANs) interconnected (linked) together, which is designed to operate over a wide geographical area. Wide Area Networks are flexible, they allow for both part-time and full-time connectivity to bandwidth, and provide access to that bandwidth through serial interfaces.

An interface, also known as a port, is the place where data is sent or received through, on a particular device.

Generally, a network is classed as a Wide Area Network when the connection between computers is established by an external method of data transport, for example, the telephone line provided by a telephone company.

There are many different types of Wide Area Networks. The largest Wide Area Network on the planet is the Internet, which consists of many Local Area Networks linked together, and subsequently millions of computers.

However, there are Wide Area Networks, which just connect Local Area Networks within the same city, country or continent.

The largest Wide Area Network in existence is the Earth-moon system, which consists of the Earth and artificial satellites. The Earth-moon system supports the Internet by making communication possible anywhere on Earth at anytime, even in remote locations, by using artificial satellites.

Overview of Data Networks

Data networks are similar to the postal system. In the postal system, letters and parcels are moved around from city to city, country to country and around the world. Each one has an address associated with it to indicate the intended destination.

They may even have a source address on it to indicate where the letter, or parcel, originated.

Data networks work, in principal, exactly the same way. Instead of moving around letters and parcels, data networks provide a transport service for units of data called packets, or data packets. These packets travel (propagate) through the networking media (wires and cables) to reach their intended destination.

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Congested Networks

In very large networks, there are thousands of data packets travelling across the network at the same time, therefore this can slow down network performance, and can cause congestion and bottlenecks as each packet queues to be processed by the router (a router is like a roundabout).

Wide Area Networks use devices known as routers to direct user traffic (data packets) and ease congestion by subdividing (segmenting) a single network into many smaller networks (also called segmentation).

As segmentation splits up a network into many smaller networks, therefore there are fewer computers on these smaller networks than the one large non-segmented network. Fewer computers mean less traffic (data packets) is generated and therefore travelling on a particular section of the network. Furthermore, as a result the availability of bandwidth is higher.

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Routing basics and how routers work in a nutshell

Routers are intelligent internetworking devices that forward data packets based upon an address, for example, an IP address.

Routers are essentially the backbone of the Internet, making communication possible between many different types of computers throughout the world.

Routers are similar to the satellite navigation system fitted in automobiles. Satellite navigation calculates the best route (path) to a destination based upon the distance (a metric). Also, if you take a wrong turn whilst travelling along a specified path, then the satellite navigation system will automatically recalculate the fastest route and direct you (switch you) to the proper path to enable you to reach your destination.

Routers calculate the best path for a packet according to numerous factors (metrics), for example, the distance to the destination and the speed of each path along the route. In routing, the distance to a destination is measured in the number of hops to the destination (the number of routers that a packet must pass through to reach its final destination).

The speed of a path depends on the amount of bandwidth allocated. Bandwidth depicts the amount of data that can travel through the networking media (wires and cables) at the same time.

Routers have numerous interfaces (ports), and they are the places where packets arrive and leave the router. Each interface is connected to a different network.

Routers create and maintain routing tables, which contain information about the paths to different networks and which port to use to forward data packets from, as each interface is connected to a different network. Furthermore, routers use routing tables to visualise the topology (structure) of the networks connected to it.

Routers use algorithms known as routing protocols, which define the rules for routers to communicate with its neighbouring routers. Basically, routers send information to its neighbouring routers, and this information includes routing tables and topology information. This communicated information is contained within routing updates, which are automatically distributed at timely intervals, for example, every thirty seconds.

The advantage of distributing routing information between routers is to provide a consistent view of a router’s connected networks to other neighbouring routers. Therefore, allowing routers to continue transmitting data accurately across a Wide Area Network.

IP Addresses get assigned to computers for network communication

When most computers join a WAN, they are assigned an address, for example, an IP (Internet Protocol) address. IP addressing is the addressing scheme used on the Internet. However, other addressing schemes exist in networking, but IP is the most popular. IP addresses are similar to postal addresses. Like postal addresses, IP addresses have a hierarchical structure. They are split into two parts: a network portion and a host portion.

The network portion of an IP address states the network the computer resides on; and the host portion is a unique number for that computer, which enables it to send and receive data packets. Each data packet sent contains an IP address of the source and the destination, therefore networking devices, such as routers; know where to send the packet.

As computers are assigned an IP address, then routers can establish which computers are on what network by analysing the network portion of an IP address. Furthermore, routers will know whether or not the source computer is on the same network as the destination. Therefore, the router will know if it needs to forward a data packet to another network in order to reach the destination computer, or just ignore the packet altogether.

PTO Switched Services Packet switching (the Internet) versus Circuit switching (traditional telephony or phone networks)

PTO switched services describe how computers connect to a Wide Area Network, and indeed the Internet. For example, there are many different connection methods – two of which are circuit-switched and packet-switched.

Circuit-Switched networks explained

Circuit-switched connection methods establish a virtual circuit between computers. The best example of a circuit-switched technology is the standard telecommunications network, or POTS (Plain Old Telephone Service).

Although POTS is not used to send and receive computer data, it is an example of a well established, reliable and easy-to-use communications infrastructure, or Wide Area Network. Furthermore, many of its technologies are part of today’s modern data networks. POTS, uses twisted pair cabling to send and receive analogue (voice) signals via the telephone line.

When you lift up the handset on the telephone, dial a number and somebody answers, there is a virtual circuit created between the caller and the receiver. This virtual circuit acts as a dedicated connection and is present throughout the duration of a call, and until either party chooses to end the call. Thus ensuring that both the caller and the receiver can reliably communicate whilst a connection is present.

Another circuit-switched technology is Narrowband ISDN (Integrated Services Digital Network). Narrowband ISDN also has its place in history, as it was the first all-digital dial-up connection. It is an extremely widespread WAN technology, although its usage varies greatly from country to country. Narrowband ISDN uses twisted pair as the medium for transporting data packets.

The availability of bandwidth varies depending on how much money is spent on the Narrowband ISDN line. For example, there are two interfaces – Basic Rate Interface (BRI) and Primary Rate Interface (PRI). The BRI provides bandwidth just over double that of a standard 56k (kilobits per second) modem – 128k to be precise! Alternatively, the PRI provides a much higher bandwidth rate – about 3 Mbps (Megabits per second). Therefore, you pay for bandwidth. The cost of Narrowband ISDN is moderate.

Packet-Switched networks explained

Packet-switched services do not establish a virtual circuit, but instead they deal with each packet individually and ensure it reaches its destination safely.

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The traditional network known as X25 had error checking capabilities and Frame Relay without error checking really took off in popularity as a Wide Area Network WAN technology

X.25 is an older WAN technology, which is still widely used and its cost is moderate. It originated when Wide Area Networks were more prone to errors, as a result it has extensive error-checking capabilities.

Therefore, it is a very reliable WAN technology, but the availability of bandwidth is reduced as every packet is checked for errors. Bandwidth may be as high as 2 Mbps (Megabits per second).

The medium for transporting data packets using X.25 is either twisted pair or fibre optic cabling. The cost is moderate.

Frame Relay is another packet-switched WAN technology. It is more efficient than X.25, although the services it provides are similar.

Frame Relay has become a very popular WAN technology, therefore usage is fairly widespread and its cost is moderate to low.

Frame Relay also has a higher bandwidth rate than X.25 – the maximum bandwidth is approximately 44.736 Mbps (Megabits per second).

Frame Relay has a higher bandwidth rate than X.25 because it doesn’t have any error-checking capabilities, thus allowing more bandwidth, and therefore gaining the ability to send more packets in less time.

The medium used by Frame Relay is either twisted pair or fibre optic cabling. Frame Relay is basically a packet-switched version of Narrowband ISDN.

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Mobile and Broadband Services - Asynchronous Transfer Mode important WAN technology and Digital Subscriber Line really started home broadband

Broadband (Broader bandwidth)

Broader bandwidth is a desirable network feature, and with more users wishing they could transmit information, or download files, quicker, this ever-increasing demand for more bandwidth is driving the need for technological advancements.

A couple of technological advancements are ATM (Asynchronous Transfer Mode) and the DSL (Digital Subscriber Line) family of technologies.

ATM (Asynchronous Transfer Mode)

ATM is a very important WAN technology. ATM is related quite closely to ISDN.

ATM has historically used twisted pair copper cabling but now uses fibre optic cabling. Its usage is widespread, and it is increasing - although the cost remains high.

DSL (Digital Subscriber Line)

DSL (Digital Subscriber Line) is a family of technologies. It was a relatively new WAN technology 20 years ago around 2002.

Furthermore, it is intended to provide high bandwidth to home computer users. However, the further away you’re situated from the telephone company’s equipment; the less bandwidth you’ll receive as the bandwidth rate decreases with increasing distance from the telephone company’s equipment.

Near telephone company equipment, users can expect to achieve fast lightning speeds in theory.

For the majority of users when broadband was first being rolled out in Scotland, lower bandwidths were commonplace, with speeds ranging from hundreds of kilobits to several megabits. Networks are getting faster and faster all the time.

ADSL (Asymmetric Digital Subscriber Line) became a very popular WAN technology, therefore making it the most popular technology of the entire DSL family.

However, its usage was limited to certain places, as telephone lines needed to be upgraded to enable ADSL.

Furthermore, it is always somewhat costly for telephone companies to upgrade everyone’s telephone lines at the same time as not everyone would purchase broadband - older people tend to be less willing to adopt newer technology.

Therefore, telephone companies tend to only upgrade telephone lines in areas where they expect to recoup the money spent on upgrading and make a profit.

These areas were known as broadband enabled areas. If you live in a broadband enabled area, then you’re a lucky sod!

There is a real role for government investment to bring about faster data networks.

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Mobile Services (including UMTS and GPRS)

The ability to access bandwidth from anywhere on Earth is a desired feature, and is the driving force for technological developments in mobile services.

UMTS (Universal Mobile Telecommunications System) is a mobile technology that delivers information.

As well as voice and data, UMTS has the ability to deliver audio and video, without the aid of wires and cables, to mobile (wireless) devices anywhere on Earth via wireless and satellite systems.

GPRS (General Packet Radio Service) is a standard for data communication via wireless devices.

GPRS has the ability to support many varying bandwidths. GPRS is good at using limited bandwidth efficiently, and is particularly suited to sending and receiving small amounts of data. For example data that is used for e-mail and generally surfing the Web. GPRS can also support the transmission of large amounts of data.

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Voice over IP and H.32x standards

Voice over IP, or Internet telephony as its otherwise known, is a means of using the Internet for telephone calls. For example, with the aid of Internet telephony software, such as Microsoft NetMeeting in the past but now Skype also FaceTime on an iPad, users can make free telephone calls anywhere in the world using their computer, provided their Internet access is free or a fixed-rate.

The drawback with using voice over IP rather than a standard telephone to make telephone calls is the result of poorer quality telephone connections - video can stutter and there is a need for compression and video compression algorithms think H265 for High Efficiency Video Coding.

H.32x is a family of communication standards, which provide for multimedia communication through many different internetworking environments.

H.32x is developed by the International Telecommunications Union – Telecommunications (ITU-T), and it provides the basis for converged voice, video and data communication across networks, which use IP (Internet Protocol).

Therefore, H.32x is merely a suite of standards (or protocols) governing the transmission of converged voice, video and data communication through IP-based networks.

Furthermore, with the combined interoperability of Voice over IP and H.32x, users can communicate with friends, or relatives, at the opposite side of the world in real-time, via the Internet, and include data and video as well as voice.

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Public Key Cryptography (PKI) Concepts - an overview of how encryption technologies work

Public Key Encryption

Public key cryptography is an important technology, which is used mainly in electronic commerce, intranets, extranets, and online applications. The main components associated with public key cryptography include encryption and authentication. Microsoft® Windows® uses public key cryptography to enhance security for areas such as smart card logon, the Encrypting File System (EFS), and Internet Protocol Security (IPSec).

Public key cryptography provides privacy and security for sensitive information through data encryption, regardless of whether the data is in the form of electronic mail messages, credit-card numbers sent over the Internet, or network traffic. As public keys can be posted freely, then this enables complete strangers to: establish private communications via public networks by merely exchanging each other’s public keys and encrypting the data.

Public key encryption consists of two keys, which are related mathematically. A key is a random string of characters, for example, a number, ASCII value, word, or phrase that is used in conjunction with an algorithm (a complex mathematical formulae). For public key encryption to function correctly, every user has a pair of mathematically related keys, including: a private key, which is kept confidential; and a public key, which is freely distributed to all potential correspondents.

The aim of encryption is to scramble sensitive data for transit through insecure public networks, such as the Internet, and only allow the data to be interpreted and understood by the intended recipient. In a typical situation, a sender uses the recipient’s public key to encrypt a message. Only the recipient has the related private key to understand and decrypt the encrypted message. By making your public key available, other people can send you encrypted data that can only be decrypted by using your private key. The use of keys in PKI-enabled programs that provide data encryption is typically transparent to the user.

Public keys and private keys are related, but not identical. For example, when encrypting text using a public key, the plain text is turned into cipher text by the encrypting algorithm. Only the recipient’s private key can understand and decrypt the cipher text back into plain text because the private key is related to the public key.

Without encrypting sensitive data for transmission across a network, attackers can connect special devices known as electromagnetic radiation readers to a network, and therefore subsequently use them to grab sensitive information, for example, credit card details, as they pass along the network. With possession of this sensitive information, an attacker could use it to their advantage. In the case of credit card details, an attacker could use the information to spend excessive amounts of money, therefore as a result, running up huge bills.

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Public Key Authentication

Public key authentication uses public key cryptography to authenticate (allow permission) and verify the originator of electronic data in e-mail, e-commerce, and other electronic transactions. Public key authentication is similar to public key encryption in the sense that both use a key pair. However, instead of using a recipient’s private key to decrypt a message, the sender’s public key is used to authenticate and validate the sender of the message. A string of characters that uniquely identifies the contents of the message is encrypted with the private key to create a digital signature. A digital signature swaps the role of the private and public keys.

Digital Signatures (Digital IDs)

Digital Signatures (Digital IDs)

A digital signature, otherwise known as a Digital ID in modern terms, is a method for allowing the originator of a message, file, or other digitally encoded information to bind his or her identity to the information. The digital signature itself is a sequence of bits (binary digits) appended to a digital document when the digital document is ready for transmission across a network.

A digital signature ensures that: only the person possessing the private key could have created the digital signature; and anyone with access to the corresponding public key can verify the digital signature. Therefore, ensuring that the transmitted data has come from the owner of the digital signature, and not someone trying to falsify someone else’s identity.

An example of a digital signature in use is when you visit a Web site and you are prompted to download a file, and a dialog box informs you that a file or program that you are about to download has come from a reputable (trustworthy) source. In theory, you know that the Web site can be trusted and that you’re not going to download a file that will corrupt your system, because the Web site has a digital signature, which means that it can be trusted.

Digital signatures are readily available and anyone can purchase one. There are many commercial organisations available worldwide that sell digital signatures, or Digital IDs. One such company is VeriSign.

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Hash Algorithms can be used to encrypt information make it harder to intercept

A digital signature uses an algorithm known as a hash algorithm. Hash algorithms are complex mathematical formulas, which are designed to guarantee that if a single byte changes in the digital signature, then as a result, processing the document generates a completely different hash. When a hash has been encrypted using a public key, then any modification of the signed data invalidates the digital signature.

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Public Key Infrastructure Securing E-Commerce

Electronic commerce, usually abbreviated to e-commerce, is merely the online form of shopping. Shopping online is becoming increasingly popular with many companies choosing to sell their products online, and many consumers choosing to purchase products via the Internet rather than parading around the shopping mall, hence saving time!

Therefore, the need for a secure method of submitting sensitive personal information (financial details) across an insecure public network, for example, the Internet, whilst making online transactions is very important.

PKI (Public Key Infrastructure) is a method used on the Internet to secure online transactions to ensure that people’s financial details remain safe. PKI uses encryption to protect sensitive data (financial details, for example, bank account numbers and credit-card numbers) whilst in transit, from Personal Computers to commercial servers.

Tesco is one of the UK’s leading supermarket chains, and it’s also the world’s leading supermarket for grocery shopping online, and with home delivery! Tesco online has enforced a public key infrastructure to ensure that their consumers’ have the privacy that’s required to ensure secure online monetary transactions, whilst in the process of carrying forth their day-to-day mundane grocery shopping.

Basically, all encryption processes that take place on Tesco online are transparent to the computer user – they are happening in the background and are oblivious to most computer users. In other words, the computer user is unaware of all the tasks that take place to make encryption possible and allow sensitive data to be transmitted securely.

However, it is possible to understand whether or not a Web site transmits sensitive data securely. Web sites that transmit sensitive data securely provide the picture of a padlock on the taskbar of the user’s Internet browser. By double-clicking the mouse on the padlock, the user can view their Internet Properties Security settings for their browser. Furthermore, the user can determine whether their computer has blocked any potentially harmful cookies, or any falsified certificates.

Moreover, secure Web sites use the HTTP Secure protocol, which is determined by the HTTPS prefix in the address bar of the user’s Internet browser. HTTPS is a protocol embedded with SSL (Secure Sockets Layer) encryption. SSL is an encryption algorithm, which encrypts data to allow it to be sent securely across a network. HTTPS, with SSL, always uses the same port to send sensitive data across a network securely – that’s port 443.

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IP version 4 address space became outgrown leading to need for IP version 6 - no-one really predicted the phenomenal growth of the Internet, a network of networks even though it enabled information sharing - also high-end cars usually have hi-tech safety features before budget mass produced cars

NetBIOS (Network Basic Input/Output System) was created in the early 1980's, but is surprisingly still alive and well on many networks today. Microsoft Windows still uses it for its name resolution function (often by default), when DNS is not available. DNS is the Domain Name System and translates friendly domain names usually what a user sees in a web browser's address bar to a numeric IP address, four digits separated by dots in traditional IP version 4 addresses. IP version 6 on the go nowadays - addresses look long and complex and reason for IP version 6 addresses is solve the problem of shortage of addresses with IP version 4. The Internet took off big time better than anyone could have imagined or foreseen.

You can obtain the IP address of a Windows 10 machine or computing entering ipconfig/all from a Windows Command Prompt - search for cmd Windows search to bring up command prompt or go to Windows System menu on Windows 10 start menu. Windows 10 still most used version of Microsoft Windows in use throughout the world in May 2022 - userbase massive, most people that are buying Windows 11 among the first users are those that are technical savvy. Ever since Windows 8 or version eight, Microsoft started offering a beta previewer for free to software developers technical users also to test the core operating system Windows - Windows 8 or eight first offered for purchase for 25 pounds very cost effective. Often embracing technology earlier, experimenting results in cost savings. Waiting around for technologies to become mainstream can result in prices going higher. This is not always the case - mainstream adoption of technology can result in bringing prices down - the big issue is that in the short term some manufacturers of computing equipment and devices can make big profits expoit users take advantage of users charging exportionate amounts.

Prices do usually come down as technology ages and dates - newly released all bells and whistles iPhones very much expensive aimed at business professionals. To this end, luxuary cars usually have more safety features first - think reverse parking sensors with beeps.

British manufacturers that really sell mass market such as Ford with the Fiesta tend to not include sensors for reverse parking.

High-tech safety features in cars is often appreciated most by the wealthy - they benefit the most often, but actually there are not really any guarantees in life for safety since events can be unpredictable. Everyone needs to take care, be vigilent and help others especially those less fortunate.

In a nutshell, IP version 4 address space became outgrown leading to need for IP version 6 - no-one really predicted the phenomenal growth of the Internet, a network of networks even though it enabled information sharing.

NetBIOS Name Format and NetBIOS used in history with Microsoft Windows clients for local network communication

NetBIOS (Network Basic Input/Output System) name is 16 bytes in length. NetBIOS names are portioned into two parts: the name of the computer, which occupies the first 15 bytes, and the name of the particular service that has requested a NetBIOS name (it occupies 1 byte). As multiple services on the same computer can request a NetBIOS name, then the naming convention identifies each individual service.

NetBIOS Naming Convention

The NetBIOS namespace is only one level - in other words, it’s a flat addressing scheme. Therefore, NetBIOS names have their limitations and drawbacks, for example, every name must be unique on the network as a result of the one-level namespace - no two names can be identical on the same network. In contrast, the DNS namespace as multiple levels - it’s hierarchical, a tree structure - as DNS uses a Fully Qualified Domain Name (FQDN), which includes the name of the host together with its domain name.

NetBIOS Resolution Methods

The NetBIOS name resolution process involves resolving a NetBIOS name to an IP Address. There are several methods of resolving a NetBIOS name when using the Microsoft implementation of TCP/IP:

NetBIOS Name Cache

The NetBIOS Name Cache consists of recently resolved NetBIOS names and their corresponding results. Name resolution can be performed quicker if the NetBIOS name has already been resolved recently and the results reside in the NetBIOS Name Cache.

NetBIOS Name Server

The NetBIOS Name Server consists of a database, which contains a list of NetBIOS names and their corresponding IP addresses. Furthermore, the server can respond to client requests for name resolution.

Local Broadcast

A NetBIOS client can broadcast across the network in an attempt to discover the IP address of the destination NetBIOS name. The host that owns the NetBIOS name replies to the source of the broadcast with its IP address. Then, the host that initiated the broadcast can connect and communicate with the host that owns the NetBIOS name.

Static NetBIOS Names

When using static NetBIOS names, the quickest way to resolve those names to an IP address is to manually enter the name-to-address mapping information into an Lmhost file - a local text file. Then, configure the client computers to lookup the Lmhost file when a request to resolve either a NetBIOS name to an IP address, or vice versa, arises.

WINS Name Registration for Microsoft Windows Historical Name to Address Mapping for computers that has slid out of use

NetBIOS traditionally resolved names over a network by sending broadcast query messages over TCP/IP. NetBIOS most notably is non-routable - this means it cannot pass through routers and traverse the Internet, a network of networks.

Understanding historical developments in computing is still important to provide context, chart developments explaining why changes and improvements really happened. Privacy issues often very sensitive - worth remembering that privacy drove German encryptions and the need to break codes during the second world war - the British code breaking effort took place at Bletchley Park in Milton Keynes. Privacy often masks crimes abuse also - those with nothing to hide do not fear speaking openly.

NetBIOS name resolution cannot happen over multiple networks. To remedy this, Microsoft developed a NetBIOS Naming Service or what most call WINS to resolve names across routed networks.

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How a WINS server worked in practice

A WINS client configuration must include an address for a primary WINS server, and possibly the address of a secondary WINS server.

During initial system start-up, typically a WINS client registers its NetBIOS name and an IP address by sending the WINS server a name registration request.

If the contacted WINS server is available and if another WINS client has not already registered the NetBIOS name, then the server returns a successful registration message to the WINS client.

Contained within this message is the amount of time until the NetBIOS name expires, also known as the TTL (Time To Live). Furthermore, the WINS server stores the name-to-address mapping information of the WINS client in its database.

If the NetBIOS name is already registered in the WINS database, the WINS server sends a name query request to the currently registered owner to ensure that the computer that owns the name remains active. The WINS server sends the request three times. If the registered owner sends a response indicating that it is still alive, then the WINS server sends a response to the client attempting to register the name indicating that the requested name is already registered. However, if the current registered owner of the name doesn’t respond to the WINS server, then the WINS server registers the name with the IP address of the client attempting to register the name. Therefore, as a result, the WINS server sends a successful name registration response to the client.

If the WINS server is unresponsive, then the WINS client will make three attempts to contact its primary WINS server. If the second and third attempts are unsuccessful, then the WINS client will attempt to contact a secondary WINS server, if a secondary WINS server is configured on the client.

If neither the primary nor secondary WINS servers are available, then the WINS client will attempt to register its NetBIOS name to any WINS server on the network.

If there is no WINS server on the network, then the WINS client will initiate a broadcast in an attempt to register its name.

WINS Name Resolution

When a WINS client wishes to resolve a NetBIOS name to an IP address, it starts the process by looking in its name cache for the name-to-address mapping information of the destination computer to establish whether it has resolved the name recently.

If the name-to-address mapping information of the destination computer doesn’t reside in its cache, then it sends a name query request to its configured primary WINS server. If the primary WINS server is unavailable, then the client resends the request two more times.

If the configured primary WINS server fails to respond to the client that initiated the request, the client therefore resends the request to any additional WINS servers that are currently configured on the client. If the WINS server can resolve the name, it therefore responds to the client with the corresponding IP address.

If the client does not receive a response from any WINS servers on the network or if a WINS server indicates that it cannot resolve the requested name, the client therefore resorts to sending a broadcast to every node on the network.

If no computer on the network responds to the broadcast, then as a last resort the client searches the Lmhost file for the name it wishes to resolve. However, it only searches the Lmhost file if it is configured to do so.

WINS Name Release

When a WINS client no longer requires the use of a NetBIOS name, it is important that the client send a message to the WINS server, which therefore instructs the WINS server to release the name.

By shutting down a WINS client using the proper operating system shutdown sequence, or by stopping a network service, the client therefore sends a name release request directly to the WINS server for every registered name.

The name release request contains both the NetBIOS name and the IP address, therefore enabling the WINS server to remove all name-to-address mappings in its database, which are related to the client issuing the name release request.

If a WINS client has not been shutdown using the proper operating system shutdown sequence, then the WINS client does not issue a name release request for its registered NetBIOS names. Therefore, the WINS server database still contains a list of the registered NetBIOS names related to the computer that wasn’t properly shutdown. As a result, the WINS server database contains outdated information.

When another WINS client wishes to resolve a NetBIOS name, which relates to the computer that was not properly shutdown, then it will receive an outdated IP address from the WINS server. This other WINS client may even attempt to connect to the client that wasn’t properly shutdown, but the connection will fail and the user will be left troubleshooting why the connection timed out.

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Multi-homed Hosts or computers with multiple network interfaces

A multi-homed host is merely a computer that uses two, or more, network interfaces and has the ability to connect to separate network segments.

A multi-homed host can be configured with only one network adapter, or Network Interface Card (NIC), and yet still yield multiple network connection interfaces with the aid of logical adapters. For example, a demand-dial Virtual Private Network connecting offices in different geographical locations, via the Internet, could be considered a multi-homed host.

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Explaining how Routing Tables work in practice

Routers are intelligent internetworking devices, which forward data packets and provide an efficient data transport service between two or more network segments based upon information contained within routing tables.

To be specific, routers use information contained within routing tables to determine the correct destination of a packet.

Routing tables contain information about all segments to which a router is connected, and they also provide instructions on how to forward packets destined for networks that are not connected directly to the router. Generally, a routing table consists of a routing table entry per network, or a segment of a network. The routing table entry depicts where the router should send packets for a specific network.

The network destination of a routing table is used along with the netmask to match the destination IP address. The network destination could be any number within the range 0.0.0.0 (the default route) to 255.255.255.255 (the broadcast address). A router will only use the default route to send a packet if no route exists to the destination address contained within a data packet.

The netmask works in conjunction with the network destination. Basically, the netmask (also known as the subnet mask) is applied to the destination IP address when attempting to match to the value in the network destination. Furthermore, a netmask also distinguishes the network portion from the host portion, within an IP address.

The gateway is merely the address a host uses when it wishes to send a packet to another segment, or network. A gateway is either the address of a network adapter or the address of a router on the same segment as the host requesting the data transport service.

The interface is the address of the network adapter, which is forwarding the data packets.

The metric defines the overall cost of a route. If there is two, or more, routes to a destination, the metric is consulted to allow a router to establish the best path to the destination. The route with the lowest metric is usually the preferred route, and other routes are only really chosen when the preferred route is unavailable.

RIP Router Update Process Explained

RIP (Routing Information Protocol) is a routing algorithm, or a set of rules devised to enable routers to communicate topology information, for example, routing tables, with other neighbouring routers. Therefore allowing neighbouring routers to share common knowledge relating to the topology, which therefore allows routers to send packets efficiently and accurately.

Basically, routers that use RIP share routing table information with other routers in a network by announcing the contents of its routing table to all of its interfaces, and by receiving the same type of announcements from other routers. Routers that use RIP update their routing tables every 30 seconds, until all neighbouring networks are represented in a router’s routing table.

Every router that uses RIP as its routing protocol begins with a default routing table, which contains entries for networks directly connected. As the routers communicate with each other, they learn about other networks that exist.

Below is a diagram illustrating a 4-router RIP update process, where 4 routers have learned about 6 additional networks by using RIP as the routing protocol:

Router A knows about Network 1 and Network 2 before it starts using RIP to communicate with neighbouring routers. Similarly, Router B has knowledge of Network 3 and Network 4, Router C has knowledge of Network 5 and Network 6, and Router D has knowledge of Network 7 and Network 8.

When Router A learns about Routers B, C and D it sends a routing update containing routing table information relating to Network 1 and Network 2. Similarly, Routers B, C and D each send routing updates, relating to their directly connected networks, to all known routers in the internetwork.

As a result, each router has knowledge of all networks in the internetwork contained within its routing table. Subsequently all routers have now converged as the information contained within their routing tables is up-to-date and consistent with one another. Therefore, the routers can send packets through the internetwork efficiently and accurately.

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Internet IP Sharing including Internet Connection Sharing and NAT leading onto a Proxy Server

There are several technologies in existence today, which allow either full or part-time connectivity to the Internet. These technologies provide automation to the process of connecting to the Internet.

Three such technologies used to connect to the Internet include:

NAT (Network Address Translator)

Networked devices that use a private addressing scheme cannot directly connect to the Internet. Therefore, the traffic that they generate must be redirected to a device such as a Network Address Translator, also known as a NAT.

A NAT must be configured with a minimum of two IP address - a private IP address and a public IP address. The private IP address is necessary to enable the NAT to communicate with the computers that are configured with private IP addresses. The public IP address is necessary as it’s the NAT’s identity on the Internet, and the public IP address allows the NAT to access a world of information via the Internet!

A NAT only requires one public IP address because when a private client that is configured to use a NAT attempts to gain Internet access, the client becomes connected to the NAT, which therefore translates the client’s private IP address to a public, external IP address. With only one public IP address required by a NAT, then IP address registration costs are significantly reduced. This is advantageous as you can have many unregistered IP addresses used internally and have them translated to only a few public, or registered, IP addresses for cross-network communication.

NAT also hides internal IP addresses from external networks, thus protecting internal networks from security violations such as unauthorised access. The only visible IP address on the Internet is the one belonging to the NAT.

A NAT can also provide DHCP (Dynamic Host Configuration Protocol) and DNS (Domain Name System) services if no other server within the network provides them. Therefore, a NAT is a cheap way to connect a network to the Internet.

ICS (Internet Connection Sharing)

Connecting to the Internet by using ICS - Internet Connection Sharing – enables multiple computers to share a single network connection and it’s much simpler to configure than a Network Address Translator (NAT), even though its features are very similar. However, its drawback is that, unlike NAT, it provides very little configuration flexibility. Therefore, as a result, ICS is mainly used for connecting small home or office networks to the Internet.

Basically, ICS provides an easy-to-configure, but limited, interface for connecting small networks to the Internet. ICS configures NAT with predefined settings, which include a set range of IP addresses, and the dynamic assignment of IP addresses to client computers. ICS is easy-to-configure as the only requirement is to select a check box.

It is not recommended that ICS be used in a network, which consists of domain controllers, DNS or DHCP servers, gateways or systems that are configured with static (manually configured) IP addresses. If ICS was used in conjunction with a DHCP server, for example, then the DHCP server would issue IP addresses dynamically therefore overriding any IP addresses assigned to clients by using ICS. Therefore, making ICS redundant.

How a Proxy Server works

A proxy server is a networking device, which regulates the traffic between a private network and the Internet, and decides whether or not packets are allowed to pass through to reach a specific network. When a client requests a network service, the proxy server translates the request and passes it to the Internet for further processing. Finally, when a computer, which resides on the Internet, responds, the proxy server passes the network service request result to the client.

Proxy servers provide security by acting as a gateway between a private network and the Internet. One such feature of a proxy server is the ability to restrict connections.

Proxy servers can be configured to block either inbound or outbound connections, or both, based upon a specific user, program, protocol, TCP/UDP port number, time of day, domain name or IP address. Therefore, this approach protects internal networks from security violations such as unauthorised access.

Proxy servers also have the ability to cache information from the Internet. For example, if multiple users request the same Web page, the proxy server will fetch the particular Web page once, keep a copy of it in its cache and then forward it to all users that requested it. This approach therefore reduces network traffic, as the proxy server doesn’t need to fetch the Web page from the Internet for each individual user that requested it.

However, the major disadvantage of proxy servers is that the initial setup requires complex configuration tasks. Subsequently, the advantage is that proxy servers allow for full configuration flexibility.

A proxy server is similar to a NAT as both allow access to the Internet whilst restricting access to the private internal network. Furthermore, both connection methods allow private IP addresses to be used on internal networks and translated to public IP addresses for access to the Internet.

Proxy servers must be configured to use specific TCP/UDP ports that are used by protocols to send packets to the Internet. This therefore allows proxy servers to perform security checks on packets that pass through. Client computers must be configured to use a proxy server. When a client computer requests a network service, the proxy server performs the necessary tasks to either retrieve the relevant information from its cache, or send a new packet to request the required information.

In contrast, Network Address Translators (NATs) do not analyse each individual packet for security or caching purposes. NATs only modify IP addresses and port numbers, and they are transparent to client and server.

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The data encapsulation process, the four layer TCP/IP protocol stack for Internet communications with Application, Transport, Internet and Network Access Layers, the importance of audits, computer serial numbers for insurance purposes - also how to isolate where there are faults in a network with routers

Data encapsulation is where Internet Protocol datagrams or data packets units of information get enclosed in lower level frames for placing on a carrier or physical medium for sending data across a network.

Physical mediums often multiple access - this is where Carrier Sense Multiple Access comes from. Computers sense a physical medium, listen to the medium also to sense it for activity - this in essence is the basics for sending and receiving data on computer networks. For token passing networks, historical networks of the past, network nodes, end stations, computers and also the users had to wait to transmit information listening for activity on physical media and networks.

When data is sent over the Internet, data communications is handled or governed by TCP/IP - this is really a protcol stack also a system of layers whereby when data is sent, certain processing or manipulation of data happens at a particular layer.

Four main layers in TCP/IP protocol stack, a set of rules to govern or control Internet communications - the Application, Transport, Internet or Network layer (TCP/IP model uses Internet, but OSI model just a descriptive 7-layer model uses Network layer OSI model intended for teaching also education), and Network access layer or Link layer.

Link layer in TCP/IP protocol stack involves both physical media putting data signals onto a carrier and also the link layer is associated with network cards in computers which do have a physical address a MAC address.

All network adaptors USB dongles also have a unique the world over MAC address - actually routers can be configured particularly home routers to limit traffic by a MAC address. This is the best security for a home network that seeks to limit or control access to a home network including resources via physical media or a form of media a network adaptor a physical piece of computer hardware fitted in a computer.

All computers need a network adaptor, a physical device to connect to the Internet - a computer needs an adaptor even to connect to mobile data where a phone's Internet data connection is shared.

Broadly, application layer refers to users interacting with an application, typically a software application for example Outlook.com through a web browser or Microsoft Outlook also.

Transport Layer refers to use of transport protocols such as the Transport Control Protocol but there is also the User Datagram Protocol or UDP which is less reliable than TCP without error checking. IP or Internet Protocol is a connectionless protocol producing small data packets (messages usually segmented broken up sent in small segments so data can get lost in transit) so it is often paired with TCP for Internet communications to bring reliability - no use pairing IP with UDP since UDP has no built-in mechanism to check for errors handle errors also.

The Network layer protocol or the Internet layer deals with IP packets in essence and addressing for each data packet or datagram including the assigning of IP addresses for source and destination. Internet layer really essential layer for the proper routing of Internet traffic this is why routers work or function at this layer.

The Data link layer of the TCP/IP protocol stack does involve putting signals on the carrier - this is the physical medium that carries data signals wireless media often the carrier when wireless networks are employed, implemented, deployed and used. The Data link layer often involves encoding in essence of data signals - this is what network adaptors handle to a great extent and all network adapters the physical cards in computers have physical real world MAC address imprinted as long numbers known as a serial number.

A MAC address is not to be confused with the physical serial number which comes on computer motherboards or detected with free Belarc Advisor software available for download which is useful for insurance purposes of computer equipment. All computers have a serial number - this is the purpose of audits, auditing when new computers are purchesed - audits enable the documentation of computer serial numbers.

Audits have been conducted at Computers and Integration whereby all serial numbers of new purchased computers were documented - indeed this was the role of this website's author. Computers can actually last quite a long time in a stable environment and also when computer activities are not so intensive or demanding. Where users play lots of games where graphic use can be intensive, there is a need for onsite IT staff and personnel including volunteers in the case of charities to maintain computers replace computer parts.

Data encapsulation also known as framing and frame relay, Asynchronous Transfer Mode, Switched Multimegabit Data Services (SMDS), and X.25 are data encapsulation technologies - putting a message enclosing it with associated recipient and sender information to ensure data is sent and received successfully.

Framing involves IP data packets encapsulated in a TCP packet. Ethernet networks is the standard for local private networks - Ethernet frames get encapsulated in an ATM frame (Asynchronous Transfer Mode) for being sent and received over an ATM backbone. For Wide Area Networks and the Internet, protocols for data encaptulation include Point-to-Point Protocol (PPP) and High-level Data Link Control (HDLC) protocol.

Point-to-Point Protocol (PPP) is a TCP/IP protocol that is used to connect one computer system to another. PPP protcols were used with dial-up connections and are still used with broadband connections. Computers use PPP to communicate over the telephone network or the Internet.

A PPP connection exists when two systems physically connect through a telephone line. You can use PPP to connect one system to another. Point to Point connects to end points - messages sent are sent by a sender to a destination. The Internet is a network of networks with multiple switches and routers.

From the Windows 10 command prompt accessible from the Windows System menu on the Start menu, when you use the ping command, type in ping and a computer's IP address - word ping immediately followed by a numerical IP address separated by dots or full stops, you can see delay information also the number of hops messages go through - this is the backend process whereby messages travel through the Internet via multiple routers. Hops counts the number of routers a simple ping message goes through - ping is a troubleshooting command use to isolate faults, repair routers determine where in a network faults are occurring to foster repair of faults in a network. The ping command assits IT and network professionals in their core duty.

Best commands really run from a Windows 10 or version ten Command Prompt is ping and also ipconfig/all - the latter reveals a computer's IP address also shows a default gateway, which is often the router closest to a computer's location. ipconfig/all also shows DNS details - primary and secondary DNS servers also known as name servers convert domain names to IP addresses. Machines and computers communicate and talk to each other in binary using binary IP addresses - domain names are human friendly form for a computer's address. Short catchy memorable domain names is good branding, good Public Relations for advertising, marketing and selling products.

The command ifconfig on Linux computers is effectively the equivalent of ipconfig/all on a Windows 10 computer. ifconfig on Linux reveals information linked to a computer's network adapter, which is the hardward device or physical component that enables the sending and receiving of data and information putting data signals onto a physical medium known as a carrier for data signals - through the air in case of wireless networks, cables in cabled Ethernet Local Area Networks.

1970s mainframe computing - Xerox PARC was the first personal computer workstation with graphical user interfaces and mouse pointing device and Smalltalk was the first graphical application, called the Xerox Alto. The PARC inventions also included the first laser printers for personal computers, and, with the creation of Ethernet, the first high-speed LAN or Local Area Network technology to link computers together that were in a specific local area.

1973 the Alohoa network was born with support for acknowledging data communications fostering more reliable communications between computers - Bob Metcalfe’s 1973 Ethernet memo describes a computer networking system based on an earlier experiment in networking called the Aloha network.

The Aloha network began at the University of Hawaii in the late 1960s when Norman Abramson and his colleagues developed a radio network for communication among the Hawaiian Islands - this is the basis for connecting many computer networks by radio or wireless spread spectrum through the air signals whereby the air is the physical medium also known as the carrier - carrier in essence for data signals, messages and information.

The desire for computer networks was to make information sharing easier - also networks and social networks really do make communication easier broaden potential reach of educational messages. Big potential for social networks to be used for education also for newsworthy informative content.

Computer networks traditionally involve physical components hardware parts, but social networks involve real people - this is the human aspect of computing at the topmost level in network models the application layer.

Alohoa network early experiment in the development of mechanisms for sharing a common communications channel - in this case, a common radio channel. This was the core purpose for establishing the Alohoa network at its fundamental premise.

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Error checking to ensure smooth install of Windows 11 first time - Perform a Cyclic Redundancy Check or md5checksum on a downloaded Windows 11 ISO file from a Windows 10 computer also set up a Domain Controller on Windows Server

Error checking before installing Windows 11 will help you to save time, cut errors make the Windows 11 installation process run more smoothly. This is really important for IT professionals who are setting up Windows 11 or version eleven on multiple computer systems rolling it out across a network. Group Policy using Microsoft servers can install applications remotely on computers across a network from one central location also Group Policy can apply settings to users also known as restrictions seek to limit their computer activity - it may not be obvious restrictions have been applied until you get an error message. Users of organisations may be part of a domain - in domains a computer server is a domain controller. You can convert an ordinary Microsoft server to a domain controller by running dcpromo in the run box - press Windows key plus letter-R to launch Run box in Windows 10 for example.

DCPromo (Domain Controller Promoter) is a tool in Active Directory that installs and removes Active Directory Domain Services and promotes domain controllers. DCPromo, which builds forests and domains in Active Directory, is found in every version of Windows Server since Windows 2000. A group of computers often form part of a domain in Microsoft terminology and multiple domains form forests.

Cyclic redundancy checks to ensure file integrity after download are known on Linux distributions or operating systems as md5checksum.

To perform a check of file integrity on Linux, just drag the file to a terminal screen - Linux uses terminal screens, Windows uses command prompt for entering specific commands for complex operations such as ipconfig/all to view information on your network or Internet connection including your computers address known as a numerical IP address. Linux operating systems are all visual these days - the graphical user interface really emerged with the Smalltalk language.

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The Transport Control Protocol 3-way handshake for reliable communications with an acknowledgement over the Internet

The Transport Layer Protocol or TCP the reliable part of data communications that govern Internet communication and the sending of data packets which carry information.

In networks, a runt is a packet that is too small, an illegible malformed data packet that does not arrive in tact whereby the message is not readable. For example, the Ethernet protocol which is used on local networks requires that each packet be at least 64 bytes long - any data packet that is less than 64 bytes is considered a runt.

Runts are not proper data packets, are malformed data packets which can happen from errors in data - Cyclic Redundancy Checks or CRC checks often done to verify file integrity with respect to data packets of enclosed information wrapped up in data encapsulation.

Data packets consist of two parts - a header and payload data the actual message. The header contains details such as sender and receiver IP address, the numerical digit address of computers on a network usually the Internet when TCP/IP is used.

CRC checks typically done on large files download through the Internet before installation - Windows and Linux operating system files good examples of files where CRC checks are performed.

Also in the header of a data packet there is a sequence number a numeral value that enables packets to be ordered reassembed on arrival - data packets often sent in an unordered manner.

Data packets usually small - data and information sent over networks is split up into multiple segmented data bit streams in a nutshell.

If a data packet gets lost, messages and information can become corrupted unreable.

Data packets in the header also state the type of service and also contain flags. The Type of service portion of a datagram or data packet a unit of information on the Internet includes parameters specifying delay, precedence, reliability, minimum cost, throughput.

Flags used in a data packet are used to indicate a particular state of connection or to provide some additional useful information like troubleshooting purposes or to handle control of a particular connection. A key flag is ACK to acknowledge receipt of a data packet during the three way handshake process for the Transport Control Protocol to ensure reliable data communications over the Internet.

The Transport Control Protocol uses a three way handshake to establish a secure and reliable connection in respect of data communications at the most fundamental level.

Three way handshake takes place first during connection initiation phase before data is put on the carrier part of the network - a cable in traditional wired networks but more commenly these days the carrier is the air in wireless network systems also ad hoc wireless networks.

Ad hoc networks is where two or more devices talk to one another without going by the way of an access point which is more commonly these days a router in homes and businesses. Before routers there was ADSL modems as standard where downloads faster than uploads.

TCP uses the full-duplex connection to synchronize (SYN) and acknowledge (ACK) each other on both sides. There are three steps for both establishing and closing a connection. They are - SYN Synchronization Sequence Number, SYN-ACK, and ACK. A client sends a Syn Synchronization Sequence Number data packet to establish a connection, then the server receives it.

The server sends back a SYN+ACK or Syn plus Ack data packet to the client to provide confirmation the intitial packet was received with an ACK flag set to a nuemral value of one or 1. The client then sends and ACK or acknowledgement data packet which the server receives - this is what happens in the background in the typical client server model when a user computer talks or connects to a web server for example.

Full-duplex implies the sending and receiving of data over one channel. A full-duplex device is capable of two-way network data transmissions at the same time.

Half-duplex devices can only transmit one way like a one way street for traffic.

With half-duplex mode, data can go both ways, but not at the same time.

Duplex just means the ability to send and receive data over a medium - over the air wireless medium are common in WiFi networks and with mobile data.

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Connect to a Windows 10 computer also to a Chromebook to view (child) screens from an Apple or Android device also Chromebooks as dumb terminals dependent on online or cloud services

Chromebooks heavily rely on servers nowadays - this is the direction Google has taken with its Chromebook line of computers. In effect Chromebooks are dumb terminals so they do not have much processing power or indeed memory so not really suitable for video editing for example.

Citrix was a dumb terminal as was Microsoft Terminal Services. The latter was used for remote support actually - Microsoft Terminal Services enabled someone to log-in to a remote computer to administer user support. Microsoft Terminal Services became Remote Desktop services - Remote Desktop connection under Windows XP. This is what enabled remote user support - an experienced IT professional able to help computer users with administration duties giving user support also.

Remote Desktop application all but vanished from Windows 10 Home - it is available in the Professional version of the operating system. When you are ready, on Windows 10 or version ten, select Start then Settings then System then Remote Desktop, thus turn on Enable Remote Desktop.

Using Remote Desktop to control Windows 10 Professional computers form an Apple iPhone - On your Windows, Android, or Apple also known as iOS device - Open the Remote Desktop app (available for free from Microsoft Store, Google Play, and the Mac App Store). Add the name of the PC that you want to connect to, then select the remote PC name that you added, and then wait for the connection to complete.

Controlling Chromebooks viewing screens remotely using Apple or Android phones

On your Android phone or tablet, open the Chrome Remote Desktop app.

Tap the computer you want to access from the list. If a computer is dimmed, it's offline or unavailable.

You can control the computer in two different modes. To switch between modes, tap the icon in the toolbar.

Connect an iPhone to Chrome Remote Desktop - It is possible for you to control a Chromebook with an iPhone.

All you need to do is install the remote desktop extension in the Chromebook's Chrome browser and the Chrome Remote Desktop app on the iPhone. This is how you can view your child's screen on their Chromebook which they are using for school work on your iPhone.

Chromebooks as dumb terminals is significant since Aberdeen City Council has bulked shipped out Chromebooks to school pupils - lack of foresight of how valuable video editing is going to be is an issue for the newly elected SNP and Liberal Democrat Aberdeen City Council in May 2022.

With this, the emphasis is on use of digital online services is future - https://www.blackbird.video/ is an in the cloud online service that can edit video. As Blackbird says on its website - "Professional video editing in a browser. Edit anywhere, publish everywhere, be first to market, scale effortlessly and flexibly, ensure content quality and drive massive efficiencies across your organisation."

Blackbird is a commercial company but it does not let user themselves upload videos and edit them - there is also no log-in link at the time of writing 21 May 2022 implying a subscription service with professional support behind the scenes.

There is also WeVideo - https://www.wevideo.com/ the online video editor for everyone which does enable users to sign-up with an account. Online video editor, screen recorder with ability to add text and music on top of videos - text as an overlay and music in the background. Music tracks are often copyright so actually music added as a backdrop to video is usually only done by professional production studios due to the need to acquire rights to music. With WeVideo, only 5 minutes per month can be published and it is for recording screens, webcams and voice overs.

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Wide range of antennas for multi-site organisations in a city to build their own private network but Internet services can offer great savings - Virtual Private Networks can encrypt private communications mask identities also enable TV viewing from banned countries

Multiple switches and routers in a network is what enables the scaling up of networks - for large organisations even in a single site with perhaps multiple sites or a campus in a city more than one router and switch is often used - significant to note this is why there is range of antennas for radio signals and radiofrequency signals.

Antennas enable signals to be carried across the air through a vaccuum in the case of wireless signals. OMNIdirectional antennas are better enabling signals to be picked up in all directions - special and different antennas often used for installations on buildings for example for a company or organisation to connect different buildings within a city for example. A network that spans a City is known as a Metropolitan Area Network.

There are organisation owned private networks as well as the big global Internet. A larger organisation may want to share information with employees across a city in different locations using a company Intranet an internal network. Antennas multiple routers and switches can come into play here also so can virtual private networks. There are public VPNs or Virtual Private Networks that work over the Internet to really mask where users are based are coming from when accessing digital services.

VPN stands for Virtual Private Network and describes the opportunity to establish a protected network connection when using public networks. VPNs encrypt your internet traffic and disguise your online identity. This makes it more difficult for third parties to track your activities online and steal data.

It is often likely more economical for organisations to embrace the Internet rather than build their own private network across a City - with embracing digital services from commercial companies you get to oursource services shift dependencies and also leverage cloud or online services provided by big brand companies which can really make substantial savings. The other issue is distributing data in the cloud in other countries helps also data to be safeguarded backed-up in the event of a natural disaster confined to a certain part or region of the world or a specific locality.

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Tree, Ring, Bus, Star and Mesh network topologies are the main network design structures for computer networks. The Internet is a Mesh network and mesh networks offer the most redundancy, make for the most resilient information flowing networks but are harder to manage also more expensive with both equipment and human costs

The Internet is based on a mesh network topology - a topology is often how networks are arranged, organised or connected. When networks are designed, designs are often based on a set structure or network topology and there are strengths also weaknesses in respect of a particular network design or topology. Mesh network topology with redundant links can be difficult to maintain, expensive also require human resources as well as physical medium, but networks with built in redundancy can help ensure more resilient communications and greater safety also to real people at risk in conflict zones - the world is very diverse with a great mix of people and often there is conflict in various places.

Mesh network topologies can be robust, data transferred through dedicated channels or links with multiple links or pathways - faults nowadays diagnosed with sensors, embedded computing has many benefits to keeping communication pathways open and information flowing. Multiple pathways also shields where data has come from - privacy is really built into mesh network topologies. Installation of cables in hard to reach places can be difficult - cables under the Atlantic ocean in the case of the Internet, the largest network in the world spanning the globe also now also going into the depth of space with satellites and satellite links and connections. Cost of maintenance often high - there is equipment, bulky cables satellites to build in the case of global Internet also people like a salary. Human cost is pay and renumeration also some people take more risks than others can lose their lives.

Another network topology is the Star Topology where all nodes or computers are connected to a central network device - this network topology only really suited to small networks since there is a need for networks to all be connected to a central device. Connections via cable have limits - physical limts and constraints can also be expensive also. Star network topologies often used hubs and hubs often had repeaters to boost signals since delays or latency in the network caused signals to weaken - signals losing strength and breaking up is still present with wireless signals and networks. For small organisations and also charities with computer networks, replacing wired cables with wireless network technology may not be cheap - budgets and financial resources can act as real world constraints. Wireless networks bring flexibility, but with wireless signals eavesdropping and intercepting wireless signals is a real significant issue. In a star network using a hub, the sole conentration of network activity takes place around a common denominator usually a hub which is only suitable for small networks due to all network nodes or computers that belong to the network sharing a collision and broadcast domain.

Bus Topology is where all computers on a network connected or linked by a single cable. A single cable failure brings down the whole network - the Internet keeps working when one cable, network link or satellite connection breaks down or fails. Some links can be faster than others on the global Internet - upgrading links investing in higher speed, higher bandwidth links, high capacity links can improve network performance and the overall experience for the end user. This can impact user mood and frustration - faster links enable better productivity, enable real people to leverage the web and Internet make use of multimedia technologies - video often places demand on networks when shared. Towns and cities in Scotland do tend to have faster Internet than rural locations, but hard to reach rural locations can be covered by other means such as by Sky Digital, Sky broadband provided by satellites.

Multiple people accessing popular, viral shared videos takes its toll on network infrastructure - if use of video is really could to take off big time by everyone with more people shooting and sharing video, investment in networks and network technology also computing technology is important, vital even and needs to be a core focus of national governments. The Scottish government has admitted Scotland's cities are smart cities and do insist we live in a digital age.

Ring topologies also existed in network design - these networks involved the passing of a token also called token passing networks. In a ring topology, computers had to wait for their turn to transmit or send data - real people can be impatient.

Wikipedia says on ArcNet - ARCNET was developed by principal development engineer John Murphy at Datapoint Corporation in 1976 under Victor Poor, and announced in 1977. It was originally developed to connect groups of their Datapoint 2200 terminals to talk to a shared 8 inch floppy disk system. It was the first loosely coupled LAN-based clustering system, making no assumptions about the type of computers that would be connected.

In the past in history big mainframes used with large floppy disks to store data - computers gradually became smaller more mobile enabling a smartphone in a pocket also embedded computing is here with sensor technology - sensors can control traffic lights, water control systems, crop irrigation systems. Networks really developed out of the idea to make life easier and share information - very frustrating also when data storage is limited in the way floppy disks were. Multiple disks were often used making it hard for people to locate information without use of labels on disks. Google born out of the desire to organise the world's information.

Clustering in a sense enables better analysis of data ability to spot trends group similar items for comparison. Clustering is from data science says W3schools - to learn more about Clustering see https://www.w3schools.com/ai/ai_clustering.asp. Clustering would likely be useful for examining climate data to make better predictions spotting trends also. Holding data from the past no use if not shared and also not used to help prepare for unforeseen events in the future.

Networks based on Ring topologies with token passing got disturbed - individual computer users uprooted when one network node or computer got changed - always stressful being uprooted, managing change can be challenging. Technological changes usually met with disruption - and some people can resist change be fearful of change be unwilling to adapt to changing circumstances.

Tree network design topologies often resemble organisations with a management hierarchy in Scotland. Similar to a star topology where information radiates from a central network device or node also known as a top down command issuing structure. This method of organisation or structure really vulnerable to failure also collapse with subordinates rivalling also quaralling power hungry. High cost of cabling in tree network topology. With tree network design structure or topology, sometimes easier to isolate faults - prevent one fault affecting a great swathe of networked computer users. Important consider fault tolerance and redundancy in computer networks - in human networks people can become ill, sick also corrupted too.

Tree, Ring, Bus, Star and Mesh network topologies are the main network design structures for computer networks. Mesh networks offer the most redundancy, make for most resilient information flowing networks but are harder to manage also more expensive with both equipment and human costs. Important also to consider natural resources and physical limits in the world at large can influence and impact the global Internet, the major network of networks. Around 4 or four billion people connected to the Internet at the time of writing 21 May 2022 - still someway to go to connect everyone. Satellite links and cost effective links really open up digital connectivity to African families and the third world, a world where many children are underpriviledged.

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Warriers of the Dot Net video explains how data is moved across the Internet - also in the beginnings of the Internet Microsoft demonstrated abusive behaviour to suppress rivals bundling its web browser Internet Explorer with Microsoft Windows - The Internet is a mesh network topology lots of redundant network links built with routers and switches

It is May 2022 - Warriers of the dot Net website has been on the go for around twenty years with 616,206 views in YouTube video from 2011 at the time of writing 21 or twenty first May 2022, a website which has long sought to explain the importance of how data is moved around on the Internet using video, a network of networks where information or data gets sent and and received by data packets. The video clip with background space age type music as an introduction sought to make data transfer and education exciting and highlighted in an engaging manner how routers are really used to move data.

The video clip created on a non-commercial basis and also the video made clear how people - regardless of race, colour and creed - also machines were working together with good effect all across the world to enable data, information and knowledge to spread in essence. Video clips with graphics, animation and music can really teach others in an engaging way - inspire them to want to help others, connect fellow humanity.

This video made visual reference to Netscape Navigator, the basis for Mozilla Firefox and sought to reveal the dawn of the Net. Around this dawn, real rivalry took place between Microsoft Internet Explorer and Netscape Navigator - Netscape pioneer of web browser technology.

Microsoft bundled Internet Explorer with Windows to gain the upper hand, market dominance, win over users, force them to use technology from Microsoft. Still to this day in May 2022, every Scottish Council use Microsoft software really supporting a company that abused a great position of trust, took part in behaviour that manipulated users. This behaviour sparked real intense revalry and competition in the technology industry - Microsoft with the core operating system Windows, Windows XP around for the best part of a decade and dominant the world over, really gained inroads, market share, acceptance with users as the de facto dominant platform, but actually it is not really fair that Scottish Councils remain loyal to a computer firm that was abusive, commanding and domineering from the outset. This is not really fair on the manufacturers of competing computing platforms - there is the Apple Mac as an alternative platform often geared towards multimedia professionals, designers and artists. Linux is however free - Ubuntu very user-friendly most popualar Linux distribution after Android and Ubuntu comes from South Africa. Africa nations and the third world would really benefit from greater use of its software - Ubuntu is a term as Nelson Mandela revealed on video as being nice to fellow humanity - respect for others, treating others as you yourself would like to be treated. Ubuntu has a concept is at the heart of fairness, a fair society and fair justice.

Clicking links starts flow of information - IP (Internet Protocol) packets bundle data or information and packets limited in size, given sender's address, receiver's address and a description regarding what packet it really is. IP is a connectionless protocol - IP does not guarantee data delivery provide any assurances or checks as the case maybe. This is the work of TCP - Transport Control Protocol. TCP/IP is the protocol stack that oversees Internet communications, regulates it ensuring data transfer is accurate and reliable. TCP/IP is the basis for data communications at the most basic level - machine communication uses data packets and often emails have a date and time attached when they were sent and received. Human communication can be more unpredictable than machine communication, so use of computers really do bring a new layer of safety to the world.

Data packets often start on a Local Area Network - sometimes they have a Proxy server and such servers can control Internet access for users of a local network. Collisions can happen on local area networks between data packets - networks with hubs are particularly prone to data destruction due to the fact small networks with hubs share a collision and broadcast domain.

Collision Detection Multiple Access is a protocol used often on local area networks - Depending on a network node's status which is often a device such as a computer (idle or busy), each station transmits a data frame when they want in essence. However, if more than one station sends the data over a channel, there may be a collision or data conflict. Due to the collision, the data frame packets may be lost or changed. And hence, it does not get received intact by the receiver often a network station another computer for example, the recipient of data communications.

Routers bring order to network chaos in data communications.

Protocols used to oversee data communications on a local network, bring order to the uncontrolled flow of information send and received using data packets.

CSMA/CA stands for Carrier Sense Multiple Access with often Collision Avoidance and it is a network protocol for carrier transmission. Like CSMA/CD (CD for Collision Detection) it is also operated in the medium access control layer. Unlike CSMA/CD (that is effective after a collision) CSMA / CA (Collision Avoidance) is effective before a collision. Collisions between data packets happen on the Internet superhighway - routers operate at the backbone of the Internet bring order to chaos in a network-connected world.

Collision avoidance in networking mainly appears in networks with carrier sense multiple access (CSMA). This is based on the principle that nodes, computer stations, that are willing to transmit data have to listen to the channel for some time to determine whether other nodes or computers are also transmitting on the wireless channel.

Routers are often systematic and are often exact for the most part.

Routers can often act as intelligent switches also - switches more common on local area networks. Switches tend to give computers a dedicated virtual port, form a connection from computer to switch that is dedicated so no collision can happen - switched individual ports also have their own broadcast domain. In hub-based networks usually seen on small networks, network nodes such as computers broadcast across the network to every other station or computer on the network. Other computers on the small hub based network are also listening, trying to see if there is a clear pathway onto the network to transmit data to other computer. Hub-based networks are shared spaces, so this is what makes hubs really not an efficient means to manage a medium-sized network or a large network. This is why switches and routers are better for scalability - to scale up networks on a large scale for large networks with multiple lots of computer users - nowadays in May 2022 large networks can have mobile users using mobile smartphones as well as tablet computers think the Apple iPad and the Samsung Galaxy range of tablets, but there is also the Microsoft Surface tablet.

Proxy servers often used for security reasons - Internet users can access websites using a proxy server and throughout the world there are annonymouse proxy servers which seek to mask where users are coming from. Some websites and digital servers restrict users by IP address with due regard to their country of origin.

The Internet is a mesh network topology - lots of redundant network links built with routers and switches. Redundant links help ensure resilient data transmission whether it is via satellite, trans-atlantic cable or by wireless means. Data packets may not take the fastest route - also data can get lost in cyberspace. Data can often be sent anywhere in the world for less than the cost of a phone call.

Websites operate on port 80 or eighty with access allowed through firewalls on port 80 - firewalls help to provide security, shield ordinary computers and network users from danger which can come from hackers for example, those who seek to gain unauthorised access to a computer system or network.

Port 25 or twenty five is a common port used for SMTP for secure mail transfer for sending emails - SMTP is Simple Mail Transport Protocol. SMTP historically used for sending emails from computers commonly used offline, but the IMAP or the Internet Mail Access Protocol works with Outlook.com in May 2022 to enable access to emails from smartphones, tablets and computers while emails stay on email servers provided by companies such as Google and Microsoft. This helps to enable access to email from virtually anywhere with a data or computer network connection. POP3 email does not sync email with a mail server - emails are often downloaded to computers at home for example and not held on computer servers. With POP3 emails, there is more of a need to back-up emails on a computer.

POP3 emails did not used to be secured from BT British Telecommunications the phone giant or major provider in the UK providing most landlines, but then BT did add support for Transport Layer Security or TLS with SSL or Secure Sockets Layer encryption to emails sent ensuring greater security preventing or making it harder for computer users to send emails on behalf of someone else masquarding as another user - the use of usernames and passwords as really proliferated and increased to such an extent that there is actually a great burden nowadays on the average user to remember user log-in credentials. SSL or Secure Sockets Layer encryption is also what is known as HTTPS - this is the letter-S extension that provides security to personal information sent and received via secure websites marked with HTTPS. Websites that do not collect and store personal data do not actually need to use HTTPS - HTTP Hypertext Transfer Protocol or HTTP on its own is sufficient for websites that just provide information to ordinary web users. HTTPS often used on ecommerce websites where users enter debit card or credit card information.

YouTube video Warriors of the Dot Net explains the dawn of the Net, data packets and routers used on the global Internet - https://www.youtube.com/watch?v=PBWhzz_Gn10

Warriors of the Dot Net Website - video that shows how data packets traverse or move across the Internet, the data packet is the single wrapped up unit for information and data sent and received across the vast network of networks and the Internet

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How to use your smartphone as a torch and be prepared for freak weather and storms

On an iPhone X or later, swipe down from the upper-right corner to open Control Center. Or on an iPhone 8 or earlier, iPad, or iPod touch, swipe up from the bottom edge of the screen to open Control Center.

Firmly press the Flashlight button.

Drag the slider up or down to adjust brightness.

For the budget iPhone SE 2020, swipe up from the bottom left corner of your phone, and select the flashlight icon on the bottom of the screen.

Android phones all have slightly different interfaces, but to open the torch on budget Samsung devices, you swipe down from the top of the home screen. This unveils a menu of shortcut icons, in which you should find the torch. If it does not appear in the tray of five icons that first appears, swipe down again to open the full tray.

For Android budget A range of smartphones, you swipe down from the top of the screen and select the flashlight icon which resembles a torch to illuminate your surroundings in powercuts, for example.

Identifying the model of your phone can be tricky, but it is usually in the About section of your phone settings. Regardless of what phone you are using, you should be able to find detailed information about the model in the about section of the Settings menu.

How to retain data long-term

Syncing files is useful for documents – keeping everyday work files up-to-date with the ability to know when you are editing the version with the most recent changes. Nowadays, we live in a multimedia-rich age – syncing photos and videos can be useful, but likely problematic when you have a large volume of multimedia files. It is better to use USB external drives and cloud storage for long term reliable storage. It is always best not to tie data to a device. All devices can fail, data redundancy, copying files, data transfer and mirroring of data is important – use of SSD hard drives as a second drive in a computer and mirroring important data between the hard drive with the operating system on it and the second drive will likely help guard against data loss when viruses wreak havoc. Content analysis, taking the time to determine the content of documents – give them meaningful names, organise them into folders with logical names and back-up them to online storage providers can help to safeguard data from loss.

There are several reputable, good quality online storage providers, namely Google Drive, Microsoft OneDrive, Dropbox and Amazon Cloud Drive. With Amazon Photos you get unlimited storage for photos with a Prime subscription. Data storage scalability in order to achieve value for money is an issue for me personally. Microsoft OneDrive storage capacity is 1TB unless you pay through the nose for additional capacity. The answer is to spread data around – use multiple digital service providers. With this, it is also safer in terms of safeguarding data from loss in the event a company goes bust or suffers damage to servers or outage.

With BT broadband packages, you often get 1TB of cloud storage. Most households will require broadband indefinitely. Digital services and reliance on them will only increase as time marches on.

For a long time, when it comes to finances, it is never a good idea to put all your eggs in one basket. Spreading money and also data around provides for greater security.

Everyone needs a place to call home – investing in a good quality computer with multiple hard drives for copying data (mirroring it) and choosing a cloud data plan can stand you in good stead in terms of retaining data long-term. Developing nations can be affected more severely by natural disasters, so the ability to rebuild homes — build new homes — efficiently is advantageous, so this is the importance of 3D printing for homes.

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Save as JPEG for the widest possible access to image data and for compatibility with Android and Linux

HEIC is a new file format for images on the iPhone and it is intended to be for transmitting images more efficiently. In iPhone Settings, tap Camera and tap on Formats to toggle between saving images in HEIC format and JPEG. High Efficiency mode is useful for 4K video, but images are of the HEIC file type, which is not fully compatible with Linux. Android is a form of Linux, so in order to ensure the widest possible access and compatibility, it is best to select Most Compatible and save images as JPEGs. There is little difference in file sizes between HEIC and JPEG or any difference is not too noticeable

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Finding photos and videos you upload in Microsoft OneDrive and Dropbox

It can sometimes be difficult for technology users to get photos and videos off their phones and tablets – uploading to OneDrive and Dropbox offers a solution, but it can often be difficult for novices to find their photos and videos once their uploaded.

When you upload photos to Microsoft OneDrive, they are automatically put in the "Camera roll" folder, so when you access OneDrive online, search for Camera roll and from that folder you can copy or move your photos and videos somewhere else. It is good practice to move photos and videos to a new folder created with the date for reference.

With Dropbox, photos and videos get uploaded to the Camera uploads folder. If this folder does not appear on your computer, you might have to visit dropbox.com and access it via a web browser initially. Once you download photos and videos, the Camera uploads folder will likely appear on your computer.

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How to create a bootable USB flash drive to install or repair Windows 10 or 11

A bootable flash drive can be useful for reinstalling Windows 10 for example or for upgrading to Windows 11. When a flash drive is bootable, you can boot operating system installation files on the flash drive and boot the flash drive when you start or boot up your computer. You can also run System Restore from Windows 10 installation media and restore your Windows 10 system software to a precise moment in time when your computer worked previously.

To make a flash drive bootable to install or repair Windows 10 or 11:

  1. Run command prompt as administrator, then type in the following commands line by line pressing Enter each time
  2. diskpart
  3. list disk
  4. select disk x (where x is the disk number)
  5. clean
  6. create partition primary
  7. select partition 1
  8. active
  9. format fs=fat32
  10. assign
  11. exit

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Preserving data, videos and embracing a digital identity while staying mobile

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News with a focus on disability and technology

Press and Journal — New 3D printing tech allows trainee surgeons to practice at home (22 July 2021)
Custom glasses: Will 3D-printing change our eyewear?
Check out this amazing 3D-printed house in the Netherlands (4 May 2021)
3D-printed homes turn sludge into shelter (2018)
Dutch couple become Europes first inhabitants of a 3D-printed house
The worlds first family to live in a 3D-printed home
Amazon Fresh till-less grocery store opens in London (4 March 2021)
BBC News — Jason Liversidge, a man paralysed from the neck down with motor neurons disease sets mobility vehicle world speed record (2020)
MSN — Jet suit for paramedics could see patients reached in minutes by a flying medic (2020)
Exoskeleton helps people with paralysis to walk (2019)

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Best iPad Apps

The Apple iPad is the most popular tablet computer of its kind and there are a wide range of apps in the Apple App Store for it.

This guide lists the 34 best iPad apps as deemed by the author.

All the apps included in this guide offer a range of features and functionality so that you can get the best out of your iPad.

Contents

In a nutshell, the apps in this guide will help you to:

Watch TV and online videos

The following apps will allow you to watch both catch-up and live TV as well as online videos:

Listen to the radio and music

The following apps will allow you to listen to your favourite radio stations from across the world as well as from the BBC:

Get the latest news and weather as well as read ebooks

The following apps will help you to stay up-to-date with international news as well as the weather forecast:

Communicate with your family and friends

The following apps will allow you to stay informed about what your family and friends are up to as well as talk to them directly:

Create documents, spreadsheets and presentations, plus back-up your photos to the cloud

With your iPad you can create documents, spreadsheets and presentations just like on your desktop computer or laptop.

The following apps are useful for just this purpose:

Shop online

Shopping online is a popular pastime for many people.

The Amazon app is the best shopping app for the iPad as you can buy a wide range of products.

Play Scrabble-like games

If you want mind boggling fun, then you might like to play Scrabble-like games on your iPad.

The following apps are good fun on your own or against family and friends:

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How to find good stuff on the Internet

Preface

Far too often when you search the web, you get thousands and even millions of search results. It is impossible to filter through them. For an Information Professional, 200 search results is considered a manageable number to sift through. This web page seeks to provide a way to get your web search results down to a manageable number. It will teach you about special operators you can use in your searches so that you end up with relevant results. In short, this web page will teach you how to find good stuff on the Internet.

Principle 1 — identify the user community for the information retrieved

When you plan a search, you should carefully work out the level of information to retrieve. For example, is the information for an adult or a child.

Principle 2 — use unique, specific terms

When searching the web, you’ll get more relevant results if you use unique, specific terms. For example, lung cancer is a broader term than pneumonia.

Let’s say we want to search for cases of pneumonia in children in Scotland. A straightforward Google search for that yields 753,000 results. Clearly, sifting through all those is not manageable and would take far too long.

By placing "pneumonia in children" in parenthesis or quotes and searching for cases of "pneumonia in children" in Scotland yields 383,000 results. As you can see that has more than halved the number of search results. That said, it is still a vast amount of information to sift through.

Principle 3 — filter the results through the lens of a specific domain

Given that hospitals use the .org domain ending, we can use that to further narrow down the search results. In other words, we can just search across all the .org domains in the country.

To do that we type in: cases of "pneumonia in children" in Scotland:.org. Notice the :.org at the end of the line. This further reduces the number of search results down to 41,100. Clearly, the search is going in the right direction.

Principle 4 — Use AND to narrow a search

The use of the word AND narrows a search. So, by changing the search string to cases of "pneumonia AND children" AND Scotland:.org, the end results are narrowed down to just 3 results. Clearly, this is much more manageable. That said, the results are nonsense.

Note that OR widens a search and NOT refines by exclusion. For example, not in Glasgow would eliminate Glasgow from the results.

Principle 5 — Try changing the domain ending to .ac.uk for academic results

If I change the domain ending to .ac.uk and search for cases of "pneumonia AND children" AND Scotland:.ac.uk, the results are widened to 13,700. This clearly shows that there are more results in the academic domain .ac.uk for what we are looking for.

Principle 6 — Use the plus ( + ) operator to include the word AND in the search

Often the words "and" and "the" are ignored by search engines such as Google. But, by placing a plus ( + ) before the word "and", the word "and" is in fact included in the search. So, doing a search for cases of "pneumonia +AND children" +AND Scotland:.ac.uk reveals a mere 6 results. Clearly, this is more manageable. The results are still nonsense, but you can at least appreciate how to narrow a search.

Principle 7 — Use appropriate sources when searching

To effectively search for cases of pneumonia in children in Scotland you would really be better using public health sources, such as MEDLINE. That said, MEDLINE is an American database, so probably not the best choice of source for medical searches involving Scotland. This is the crux of the point. You need to use appropriate sources for effective searching.

Specific Google searching

For searches involving Google, you can:

Best Practices for Google searching

Useful sources of information