2/11/09

What is a Protocol?


What is a Protocol?
As we have been stating all along this blog, in order to communicate it is necessary to have rules that standardize the use of elements in order to create meanings. In this way, protocols are the rules that make computers create syntax and semantics using their information to communicate among them.

Each protocol helps to guide the machine into the communication with other computer or special device (such as a printer, a scanner, a telephone, a camera, a thermometer) in order to achieve a specific objective. This means that while each protocol is designed to enable communication of different things, its operation is similar.

How does it work?
In a first stage, a protocol helps to detect an underlying physical connection. Once it is established there is a node or an endpoint, it comes the “handshaking” which in telecommunications refers to a process in which the computer negotiates the parameters of communication channels, in other words, computer is verifying response on the other device and “talking” to it to make sure there exist a common language in order to transfer data.

After knowing there is possible to communicate with the other device, the protocols checks: 1) the negotiation of the connection characteristics, 2) the procedures to start, end and format a message, 3) what should be done if any problem happens while sending a message (such as noticing if there is a corrupted or a not well formatted message) or what happens if suddenly is detected a loss of connection and finally 4) how to terminate a session or connection.

What is it for?
Is more understandable the function of something by know what will happens if that something does not exist. The protocols were created to make it possible the communication between the computer with other hardware or software or between software with other software. In other words, without protocols it would not be possible to have any communication between machines or the programs it uses. Thanks to the protocols we can print, we can connect to Internet, we can watch satellital TV, we can transfer data and the telecommunications have developed so fast.

PICS

We recommend:
NATALIA OLIFER, Computer Networks: Principles, Technologies and Protocols for Network Design
GERARD J. HOLZMANN, Design And Validation Of Computer Protocols