< < E-NEF > >

Prog. Perl | Art Roman | Voyager | Cartes

port

 
Generally speaking, a computer has a single physical connection to the network. All data destined for a particular computer arrives through that connection. However, the data may be intended for different applications running on the computer. Through the use of ports, the computer knows to which application to forward the data.
Data transmitted over the Internet is accompanied by addressing information that identifies the computer and the port for which it is destined.
The computer is identified by its 32-bit IP address, which IP uses to deliver data to the right computer on the network.
Ports are identified by a 16-bit number, which TCP and UDP use to deliver the data to the right application.
In connection-based communication such as TCP, a server application binds a socket to a specific port number. This has the effect of registering the server with the system to receive all data destined for that port. A client can then rendezvous with the server at the server's port.

Port numbers range from 0 to 65,535 because ports are represented by 16-bit numbers. The port numbers ranging from 0 - 1023 are restricted; they are reserved for use by well-known services such as HTTP and FTP and other system services. These ports are called well-known ports. Your applications should not attempt to bind to them.

© Copyright 1998-2005 Emmanuel PIERRE. Libre reproduction sous Licence LLDDv1. Pour tout commentaire, webmaster@e-nef.com Dernière MaJ 15/12/2017