Network Protocols

A protocol is an agreed set of rules for transfer of data. It will include the carrier signal frequency and voltage to be used, number of bits per second to be sent, whether the transmission is to be duplex (both directions simultaneously), half-duplex (data in both directions but only one direction at a time) or simplex (data in one direction only), how transmission is to be initiated and terminated, error detection and handing and so on. When two devices communicate they must agree on the protocol to be used. A particular device may be able to communicate according to a variety of protocols and it will be configured by the user or by software for use in a particular instance.

Computers communicate all over the world. The computers will have different processors, operating systems and data storage formats, each having been produced by a different manufacturer to different specifications. If they are to communicate effectively then there must be internationally agreed standards. The standards will incorporate agreed protocols. The ultimate aim is for Open Systems Interconnection. This would allow any system to communicate with any other system irrespective of the user platform. International agreement on open systems interconnection has begun to develop from the OSI seven layer model of communication.

© LEV