Introduction to TCP/IP
Transmission Control Protocol/Internet Protocol (TCP/IP) is an
industry standard protocol stack that is used for communication
between Windows 2003-based computers. TCP/IP is designed for
communication across
large-scale networks. The tasks involved in using TCP/IP in the
communication process are distributed between protocols that are
organized into four distinct layers of the TCP/IP stack. Each
protocol in the TCP/IP stack has a distinct role in the
communication process.
During the communication process, many applications may be in
communication at the same time. TCP/IP has the ability to
differentiate one application from another. TCP/IP identifies an
application on one computer and
then
moves the data from that application to an application on another
computer.
TCP/IP
Layers
TCP/IP uses a four-layer communication model to transmit data
from one location to another. The four layers in this model are
application, transport, Internet, and network interface. All
protocols that belong to the TCP/IP
protocol stack are located in these layers of the model.
Application Layer
The application layer is the topmost layer in the TCP/IP stack.
All applications and utilities are contained in this layer and
use this layer to gain access to the network. The protocols in
this layer are used for the formatting and exchange of user
information. They include:
-
Hypertext Transfer Protocol (HTTP)
HTTP is used to transfer files that make up the Web pages of the
World Wide Web.
-
File Transfer Protocol (FTP)
FTP is used for interactive file transfer.
Transport Layer
The transport layer provides the ability to order and guarantee
communication between computers and passes the data up to the
application layer or down to the Internet layer. The transport
layer also specifies the unique identifier of the application to
which data is to be delivered.
The transport layer has two core protocols that control the
method by which data is delivered. They are:
-
Transmission Control Protocol (TCP)
TCP guarantees the delivery of data through an acknowledgement.
-
User Datagram Protocol (UDP)
UDP provides fast delivery of data but does not guarantee data
delivery.
Internet Layer
The Internet layer is responsible for addressing, packaging, and
routing the data that is to be transmitted. This layer contains
four core protocols:
IP is responsible for addressing the data to be transmitted and
getting it to its destination.
-
Address Resolution Protocol (ARP)
ARP is responsible for identifying the media access control
(MAC) address of the network adapter on the destination
computer.
-
Internet Control Message Protocol (ICMP)
ICMP is responsible for providing diagnostic functions and
reporting errors due to unsuccessful delivery of data.
-
Internet Group Management Protocol (IGMP)
IGMP is responsible for the management of multicasting within
TCP/IP.
