TCP/IP Overview

Computer network protocols are formal rules of behavior that govern network communications.
The Transmission Control Protocol (TCP) and Internet Protocol (IP) are
just two of the data communication protocols encompassed by the Internet Protocol
Suite. This protocol suite is usually referred to as TCP/IP partly because TCP and IP
are two of the most important protocols of the collection. TCP/IP includes a set of standards
that specify how networked computers communicate and how data is routed
through the interconnected computers.
TCP/IP provides the application programmer with two primary services: connectionless
packet delivery and reliable stream transport.

TCP/IP has several distinguishing features that have led to its popularity,
including
Network Topology Independence. TCP/IP is used on bus, ring, and star
networks. It’s used in local-area networks as well as wide-area networks.
Physical Network Hardware Independence. TCP/IP can utilize Ethernet,
token ring, or any number of physical hardware variations.
Open Protocol Standard. The TCP/IP protocol suite standard is freely
available for independent implementation on any computer hardware platform
or operating system. TCP/IP’s wide acceptance and the fact that TCP/IP is
available on platforms ranging from supercomputers to desktop personal
computers makes it an ideal set of protocols to unite different hardware and
software.
Universal Addressing Scheme. Each computer on a TCP/IP network has an
address that uniquely identifies it so that any TCP/IP enabled device can
communicate with any other on the network. Each packet of data sent across a
TCP/IP network has a header that contains the address of the destination
computer as well as the address of the source computer.
Powerful Client-Server Framework. TCP/IP is the framework for powerful
and robust client-server applications that operate in local-area networks and
wide-area networks.
Application Protocol Standards. TCP/IP doesn’t just provide the programmer
with a method for moving data around a network among custom applications.
It also provides the underpinnings of many application-level protocols
that implement such common functionality as e-mail and file-transfer capabilities.
The current incarnation of the Windows Sockets library is built on TCP/IP, although
there’s nothing inherent in WinSock precluding it from utilizing an alternate protocol stack. In fact, work is in progress on the next version of WinSock, which will support
the use of Novell’s IPX/SPX, Apple’s Appletalk, and other popular network protocols.