A brief history of the internet

What are the three classes of networks?

(small number of networks with large numbers of hosts) ↓ Class A - Large, national scale networks Class B - Regional scale networks Class C - Local area networks ↓ (large number of networks with relatively few hosts)

The history of the internet revolves around four distinct aspects. Name these aspects.

1. Technological revolution based on research on packet switching 2. Operations and management aspects of maintaining a global network infrastructure 3. Social aspect (internet users who create and evolve the technology) 4. Commercialisation of the internet

Two key steps along the path towards computer networking

1. Using packets rather than circuits 2. Making the computers talk to each other

First network as an example of the internet?

ARPANET

Why were RFCs helpful?

Academics and the research community promoted the transferance of publications and notes surrounding the internet, however traditional academic publication was too formal and time-consuming. Request For Comments were informal notes that were initially printed and sent between network researchers, but are now available online.

Why was a 32 bit IP address not enough to cover all networks on the internet? (note this can handle 256 networks)

Because the proliferation of LANs were not accounted for (Local Area Networks)

Why was the DNS necessary?

Domain Name System Due to a large number of hosts of networks (LANs), a single table listing the host names and addresses was not sufficient. The DNS permitted a scalable distributed mechanism for resolving hierarchical host names (e.g. www.acm.org) into an Internet address.

What was the initial 'hot application' of the ARPANET?

Electronic mail/ email

What were some of the planned initial functions of the internet?

File sharing and remote login

what does IP stand for?

Internet Protocol

Packet vs circuit switching networks

Packet switching is when blocks of data are broken down into 'packets', which then travel to the destination on the fastest available circuit. Each packet may take a different route, however are all encoded to end up at the same place. (e.g. broadband internet) Circuit-switched networks reserve a dedicated channel for the entire communication. (e.g. telephone lines/ dial up) on a circuit-switched design, networks would interconnect at the circuit level, passing individual bits on a synchronous basis along a portion of an end-to-end circuit between a pair of end locations

What is an RFC?

Request For Comment

How was the internet able to develop beyond solely the ARPANET network?

The Transmission Control Protocol/Internet Protocol (TCP/IP). This supported an open-architecture network environment, where external networks could interact with each other despite having different designs and user interfaces. Therefore no internal changes could be required to any network to connect it to the Internet.