Datasheet

“main” (Installation and Administration) — 2004/6/25 — 13:29 — page 414 — #440

21.1 TCP/IP — The Protocol Used by

Linux

Linux and other Unix operating systems use the TCP/IP protocol. It is not

a single network protocol, but a family of network protocols that offer vari-

ous services. TCP/IP was developed based on an application used for mil-

itary purposes and was deﬁned in its present form in an RFC in 1981. RFC

stands for Request for Comments. They are documents that describe various

Internet protocols and implementation procedures for the operating system

and its applications. Since then, the TCP/IP protocol has been reﬁned, but

the basic protocol has remained virtually unchanged.

Note

The RFC documents describe the setup of Internet protocols.

To expand your knowledge about any of the protocols, refer

to the appropriate RFC document. They are available online at

http://www.ietf.org/rfc.html.

Note

The services listed in Table 21.1 are provided for the purpose of exchanging

data between two machines via TCP/IP. Networks combined by TCP/IP,

comprising a world-wide network are also referred to, in their entirety, as

“the Internet.”

Table 21.1: Several Protocols in the TCP/IP Protocol Family

Protocol Description

TCP Transmission Control Protocol: A connection-oriented

secure protocol. The data to transmit is ﬁrst sent by the

application as a stream of data then converted by the

operating system to the appropriate format. The data

arrives at the respective application on the destina-

tion host in the original data stream format in which it

was initially sent. TCP determines whether any data

has been lost during the transmission and that there

is no mix-up. TCP is implemented wherever the data

sequence matters.

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