Title: Internet, the Network of Networks
Course: Informàtica 4t ESO v2 ang > Section: Topic 6. Networks and Device Connections

Internet, the Network of Networks

Internet

Internet is a network of networks of all types distributed across the planet, with means of transmission ranging from copper wire to satellite.

Internet has a topology in the form of a network or web such that communication between two computers can be transferred via different alternative routes. This feature is determined by its origins in the US military sphere where the technology was developed during the Cold War with the Communist bloc throughout the 1960s. The thesis on which it was designed was that communication between two computers can intelligently circulate through different sections and nodes even when some sections and nodes have been damaged by a hypothetical enemy attack. This preliminary network was called ARPANET (Advanced Research Projects Agency).

The technology reached its way to civil society, first via research networks at universities and then on to the public at large in the 1990s.

Communication between a domestic computer and a server. Source: Wikimedia

TCP/IP protocols were developed to enable communication with a diversity of networks, computers and operating systems.

The connection between a computer or network to the internet is done through a device called a modem which acts as an intermediary between the local network and the phone line. This is the function of the router in a domestic installation.

Internet access

Internet access is provided by Internet Service Providers (ISPs) that are usually the same as the telephone companies.

There are different access technologies. The most popular is ADSL (Asymmetric Digital Subscriber Line), which uses copper wire telephone lines. The word ‘asymmetry’ in the name comes from the different transfer rates allowed in each direction. The rate is very small when the information is going from the client to the server (uploading information) and very large in the opposite direction (downloading information). The transfer rate is not constant and can vary for different factors. The nominal rate the ISP provides indicates the maximum possible speed.

There are applications on the internet that measure the speed instantly, in addition to the ISPs’ own ones. Try it out below: ADSL test .

Activity: measure your Internet connection speed.