2. USAGE CONSIDERATIONS › 2.2 General Analysis Considerations › 2.2.4 TCP/IP Overview

2.2.4 TCP/IP Overview

Transport Communication Protocol/Internet Protocol is a set
of industry standard protocols and applications that allow
you to share data and computing resources with other
computers.  By using TCP/IP commands at your workstation,
you can perform tasks and communicate easily with a variety
of other systems and workstations.  TCP/IP allows you to
perform tasks independent of the computer types involved
in the communication.

The TCP/IP protocols connect equipment from different
vendors.  It is capable of running over many different types
of media and data links.  It combines a set of networks
into a single network.

TCP/IP provides several common services across multiple
platforms.  These services are:

o Electronic Mail (Email)
o File Transfer
o Telnet or Remote Logon

The specific structure selected for TCP/IP protocols was
dictated by requirements that evolved in academic and defense
communities.  IP does what is needed to glue different
networks into an internet.  TCP provides reliable data
transfer.  In a layered model, IP protocol follows Physical
Layer (The physical layer deals with physical media,
connectors, and signals that represent 0s and 1s.) and Data
Link Layer (At this layer data is organized into units called
frames.  Each frame has a header that includes address and
control information and a trailer that is used for error
detection.).  IP protocols perform network layer functions.
It routes data between systems.  TCP layer follows IP layer.
It performs transport layer functions.  It provides reliable
data connection services to applications that were lacking at
the IP layer.  It contains mechanisms that guarantee that
data is delivered error-free, without omission, and in
sequence.