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Lesson 6 Understanding Internet Protocols
Objective Describe protocols.

Describe Internet Protocol

If the Queen of England visited the President of the United States, there would be a reception full of ambassadors and other politicians at the White House. Who sits where, who introduces who, what people say when they greet the Queen or the President or when they say good bye would follow a strict set of rules that are known as "protocol." These rules (and their order!) are very important in the world of diplomacy. Failing to follow them could actually be taken as an offense and even break relations between countries.
Protocol establishes strict order to how things are done, as in the series of diplomatic customs discussed above. And the Internet is not an exception. To be able to send and receive information over the Internet, specific protocols have been developed which dictate precisely the order and method in which it is performed. Internet protocols are easier to master than diplomatic protocols, because their rules are strictly logical.

What is a Protocol?

A protocol is a set of logical rules that define how computers send and receive information, so that two computers can exchange data. There are two types of protocols: proprietary and open. Proprietary protocols are vendor-specific; that is, they are particular to a specific vendor. For example, MS Windows Networking works on Windows based computers, and AppleTalk works on Macintosh computers.
Open protocols are published specifications that anyone can use. For example, TCP/IP, HTTP, and FTP work on UNIX, Windows-based computers, and Macintosh computers.

The Nature of Protocols

Protocols can be either connectionless or connection-oriented. Connectionless protocols do not maintain their connection to the client[1]. After data is transmitted, the client and server disconnect. If the user requested additional information, the client/server connection would have to be reestablished. UDP is an example of a connectionless protocol. A connection-oriented protocol establishes a virtual circuit to begin a conversation and sequences and acknowledges all transmitted data.
TCP/IP is also used on intranets inside many companies. TCP[2] is an example of a connection-oriented protocol. After data has been transmitted, the client remains connected to the server. The client must end the session in order to break the connection.

The following Slide Show illustrates the protocol process:

Protocol Information
In the next lesson, two particular protocols, UDP and TCP/IP will be discussed.
[1]Clients: A computer (CPU, hard drive, and monitor) configured to receive data on a network. Clients host the browsers that access and display Web resources.
[2]TCP/IP (Transmission Control Protocol/Internet Protocol): One of the main protocols used on the Internet for transferring information from computer to computer.