TCP/IP is the acronym that is commonly used for the set of network
protocols that compose the Internet Protocol suite. Many texts use the term
“Internet” to describe both the protocol suite and the global wide area
network.
TCP/IP refers specifically to the Internet protocol suite.
“Internet” refers to the wide area network and the bodies that govern the
Internet.
TCP/IP consists four layers :-
-
Host-to-Network
(Physical + Datalink layers of OSI) or Network Interface Layer.
-
Internet
layer
-
Transport
layer
-
Application
layer (Session + Presentation + Application layers of OSI)
Host-to-Network layer (or Network Interface
Layer):
It does not
define any specific protocols. It
support all the standard and proprietary protocol.
Network layer:
TCP/IP support Internetworking Protocol (IP) in turn uses four
supporting protocols ARP, RARP, ICMP and IGMP.
IP (Internetworking Protocol): it is the
transmission mechanism used by TCP/IP. It is unreliable & connectionless
protocol, a best effort delivery service.
The term best effort means that IP provides no error checking
or tracking. IP assumes the unreliability of the underlying and does it best
to get transmission through to its destination, but with no guarantee.
ARP (Address resolution protocol): It maps logical address (IP
address) to the corresponding physical address (MAC address).
RARP (Reverse ARP): Maps physical tp logical address.
ICMP (Internet Control Message Protocol) : It is a
mechanism used by hosts and gateways to send notification of datagram problems
back to the server. ICMP sends query and error reporting message.
IGMP (Internet Group Message Protocol): It is used to facilitate
the simultaneous transmission of a message to a group of recipients.
Transport Layer:
Traditionally
the transport layer was represented in TCP/IP by two protocols TCP & UDP,
but a new transport layer protocol SCTP has been devised to meet the needs of
some newer applications.
-
IP is a host-to-host protocol, meaning
that it can deliver a package from one physical device to another.
-
UDP and TCP are transport layer protocols responsible
for delivery of a message from process (running program) to another process.
-
TCP (Transmission Control Protocol): It is Connection
oriented reliable protocol.
-
UDP (User Datagram Protocol): It is Connectionless
unreliable protocol.
-
SCTP (Stream Control Transmission Protocol):
Provides support for newer applications such as voice over the internet. It
combines the best features of UDP & TCP.
Must Read This Also......OSI Model