|  | 2.1 | General Model of Communication
| 2.1.4 | Protocol

In order for data packets to travel from a source to a destination on a network, it is important that all the devices on the network speak the same language or protocol. A Protocol is a set of rules that make communication on a network more efficient. Some common examples are as follows:

- In Congress, a form of Roberts Rules of Order makes it possible for hundreds of representatives, who all like to talk, to take turns, and to communicate their ideas in an orderly manner.
- While driving a car, other cars (should!) signal when they wish to make a turn; if they did not, then the roads would be chaos.
- While flying an airplane, pilots obey very specific rules for communication with other airplanes and with air traffic control.
- When answering the telephone, someone says, "Hello," then the person calling says, "Hello. This is.... "; and so it goes back and forth.

One technical definition of a data communications protocol is: a set of rules, or an agreement, that determines the format and transmission of data. Layer n on one computer communicates with Layer n on another computer. The rules and conventions used in this communication are collectively known as the Layer n protocol.

| Web Links
| The OSI Reference Model