Networks: the internet and how it works
Overview
Most of us use the internet every day, but not all of us take the time to think about how it works. In fact, many of us will only notice when it doesn’t work. So what is the internet?
This article will cover:
Networks and the internet
Measuring internet speeds
Uploads and downloads
Cable or wi-fi?
Networks and connections
Developing
What is a network?
In computing, a network comprises two or more devices that can communicate. A computer network is made up of a number of different computer systems connected by physical and/or wireless connections. The size of a network can range from a single home computer linked to other devices like a printer, to huge data centers that connect across the world, and to the whole of the Internet itself.
All networks allow computers to share information and resources.
What is the internet?
In simple terms, the internet can be defined as a group of interconnected networks. More specifically it is now the global network of computer networks using standard rules for how information is exchanged through the internet, also known as protocols.
Skilled
How does data move around the internet?
A protocol is a set of rules that computers can follow to complete tasks. The Transmission Control Protocol and the Internet Protocol (TCP/IP) are the ones used by computers to communicate with each other. These protocols were defined in 1980 and they are what helps the Internet to move data from one place to another. Data moving over the Internet is called “packet switching.” Packet switching sends data in separate pieces (these are the “packets”) which are tagged with your intended destination.
In 1989 Tim Berners-Lee proposed a new information management system at CERN. In 1991 it was launched as the World Wide Web (WWW, aka 'the web'). The Internet can be seen as the backbone of the web – what makes the web possible.
Both hardware and software support the Internet. Types of hardware include routers, servers, phone towers, satellites, and smartphones. Types of software include browsers, such as Explorer or Chrome. Introduced in 1993 the browser made the internet and web available to a mass audience.
Measuring internet speeds
You can measure the connection speed and quality of your connected device to the internet with an internet speed test. There are a few different ones available online. For example, test the speed of your connection by clicking on this link: http://www.speedtest.net/ Make a note of the speeds then check wi-fi, mobile phone and cable differences, both at home and on campus. Compare the speeds when you change your access type. Consider the difference between these speeds and the different networks described below.
What would you consider a 'fast' connection? A 'slow' one?
Uploads and downloads
Pay attention to upload vs download speeds - these can be quite different and will affect your experience of the internet, as most domestic internet connections limit upload speeds.
Network contstraints
Networks have physical properties. Look at these websites that address some of the factors that affect network speeds:
Time of day - https://www.accc.gov.au/consumers/internet-landline-services/broadband-speeds (go to section 'Network limitations that affect speed')
Physical interference - https://www.performancenetworks.co.uk/blog/post/5-factors-can-affect-wifi-signal/ Think of a standard network connection like rope where you unwind it and hand out each strand (as users log in). The more users, the less and less rope there is to hand out. Many laptops link to an access point on the network and that access point divides up the traffic to each laptop user. Even the placement of the cables can make a difference, as interference can come from different places, such as lifts and fans. The age and quality of the cable can also have an impact on connection speeds. Speed is constrained by the slowest part of the link, which may be the connection of your laptop to the network, or the campus LAN, or even the firewall at the campus boundary. Many factors can influence the capacity of a wi-fi connection too. Can you think of any times when your wi-fi has become unstable?
Adept
Here is a list of different technologies used in Australia for connecting computers and the internet:
ADSL – domestic, small business, faster download than upload
NBN – domestic (being rolled out), CBD, schools
NREN – universities, CSIRO & some GLAM, research institutes, hospitals, schools
Each of these has different properties.
ADSL
A digital subscriber line (DSL) service provides a connection to the Internet through the telephone network. Asymmetric digital subscriber line (ADSL) is a type of DSL technology. In ADSL, bandwidth and bit rate are said to be asymmetric, meaning greater toward the customer premises (downstream) than the reverse (upstream). ADSL2+ extends the capability of basic ADSL by doubling the number of downstream channels. The data rates can be as high as 24 Mbit/s downstream and up to 1.4 Mbit/s upstream.
ADSL2+ service is most commonly offered in highly populated metropolitan areas and subscribers must be in close geographical locations to the provider in order to receive ADSL2+. The further the subscriber is from the telephone exchange the slower the connection.
ADSL2+ has a maximum potential download speed of 24Mbps. Most ADSL2+ connections are much slower: the average Australian ADSL speed is just 8Mbps.
NBN
The National Broadband Network (NBN) is an Australian national wholesale open-access data network project. It is a government initiative to upgrade Australia’s broadband infrastructure to provide consumers with faster broadband connections.
Using a variety of broadband network technologies including running fibre all the way to the consumer’s premises (‘fibre to the premises’ or FTTP), or running fibre to a nearby box or apartment block and then using the existing copper telephone wire (‘fibre to the node’ or FTTN, and ‘fibre to the building’ or FTTB). The aim is to bring data closer to the end user on optical fibres. The differences between the methods have mostly to do with how close the delivery on fibre is to the end user.
NOTE: The main difference for the consumer between the NBN and ADSL is speed. There are various options for speed, depending on requirements.
This video helps explain: https://www.youtube.com/watch?time_continue=31&v=L3QJLEbUj94
NBN evening speeds
Maximum speeds are not always available due to high traffic. This table shows 'evening speeds', which is what is expected at peak usage times between 7pm and midnight.
| Tier | Maximum speed | Evening speed |
|---|---|---|
Basic (NBN 12) | 12Mbps | 7Mbps |
Standard (NBN 25) | 25Mbps | 15Mbps |
Standard Plus (NBN 50) | 50Mbps | 30Mbps |
Premium (NBN 100) | 100Mbps | 60Mbps |
Remember!
The download and upload speeds of the domestic broadband speeds factor for more download than upload. That is, it is assumed that people download more than they upload.
NREN
The National Research Network (NREN) provides advanced research network infrastructure.
It is fast, with connections from 10 Gbps to 40 and 100 Gbps.
It is high capacity, catering to 1 million + users and is tailored for research, teaching and learning. It has low latency (lag) providing consistent connectivity and response times because it is designed to have ‘headroom’ or allow for bursts (elephants) of large data moving through the network.
Australia is a large continent, and the networks AARNet provides enable data capture and research to be conducted in major cities and in regional areas, where universities and research facilities and infrastructure are located, e.g. the National Computational Infrastructure (NCI) in Canberra and the Square Kilometre Array (SKA) in Murchison (WA).
Australia lies at a distance from research conducted in other parts of the world, like the northern hemisphere, and the networks AARNet provides aid in removing distance as a barrier to research collaboration.
Click here to learn more: https://www.aarnet.edu.au/our-network
Remember!
Headroom: By capping utilization at less than link capacity, the AARNet network leaves room for latency sensitive traffic in order to avoid buffering and the associated large delays.
Helpful resources
Self-paced tutorial - Khan Academy - Computers and the Internet - Unit: The Internet
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