In the data-processing networks and the Telecommunications, a communication protocol is a specification of several rules for a particular type of Communication.

Initially, one named protocol what is used to communicate on same a Couche of abstraction between two different machines. By extension of language, one uses sometimes this word to also today indicate the rules of communication between two layers on the same machine.

The most used communication protocols are the protocols network.

Concept

To communicate consists in transmitting information but as long as the interlocutors did not allot a direction to him, it is only of data and not about information. The interlocutors must thus not only speak one common language but also control minimal rules of emission and reception of the data. It is the role of a protocol to make sure of all that. For example in the case of a phone call:

1. the interlocutor learns that you have something to transmit (You compose his number to make sound his compound);
2. it indicates that it is ready to receive (you wait until it takes down and says " Allo") ;
3. it locates your communication in its context (“I am Christophe. I call you for the following reason… ”);
4. possible a final recipient can be identified there (“Can you warn Michel that… ”);
5. the correspondent the message (“can you secure to have well included/understood repeat me the name? ”);
6. the procedures of anomalies are installation (“I recall you if I am not able to join it”);
7. the interlocutors agree on the end of the communication (“Thank you to have prevented me”).

This metacommunication is not other than the implementation of protocols .

But you already implicitly observed a other protocol, with another layer of communication, while waiting to have the tonality to compose the number of your correspondent. And arrival and the starting switchboards, for their part, coordinated each other between them also: as many protocols.

See too

Internal bonds

• Interworking