Introduction to Internetworking

Internetworking:--


•Motivation for Internetworking
–What is internetworking?
•Connect multiple networks of one or more organizations into a large, uniform communication system.
•The resulting system is called an internetworkor internet.
–notion of an unified internet
–Why internetworking?
•There are many existing networks located at different places. It is desirable to connect them together for global communication and information exchange.
•In the future, there will still be multiple types of networks, because no single network technology can fulfill all the needs. It is necessary to connect them for communication.
–E.g, multinational companies have high speed optical connections, whereas some other companies located in older buildings still use traditional thin-wire or twisted pair Ethernet connections.

–What is a protocol?
•A set of syntactic and semantic rules for communication.
•details of message formats
•How a computer should respond when a message arrives.
•How a computer handles errors or other abnormal conditions.
•Independent of lower layers or hardware
–The protocols should be transparent, hiding the details of each network and the interconnection of these networks.
•The users and application programmers are not required to know these details. They see the internet as a single, large network.
•Users' view on the internet:
TCP/IP is the most widely used internetworking protocol suite.
•TCP: Transmission Control Protocol.
•IP: Internet Protocol.
–TCP/IP is now the defactostandard for internetworking protocols.
–TCP/IP reference model:
•Network Access Layer: Specify the protocols being used in the underlying networks.

TCP/IP reference model (cont.)•Internet Layer: Define a common packet format and the internet protocol for packet delivery.•Transport Layer: Define transport protocols (transmission control protocol (TCP) for connection-oriented transport, and user datagram protocol (UDP) for connectionless transport).•Application Layer: Define application protocols such as file transfer (FTP), email (SMTP), and virtual terminal (TELNET).

Tutorial Problems
–How would your study be affected if there were no Internet?
–List some networks that you have learnt from COMP 2330.
–There are many different types of networks. Why?
–A student argues that it is better to have only one type of networks because this can avoid the overhead of protocol conversion in internetworking. Do you agree?
–What are the major functions of a router?
–Many routers are available in the market and they have different prices. What factors would determine the price of a router?
–If a router can connect to at most K networks, how many routers are required to connect N networks?