Internet Protocol - Research by Kirils Solovjovs

OSI model 39
citeseerx. ist. psu. edu/ viewdoc/ summary?doi=10. 1. 1. 136. 9497).
• Cisco Systems Internetworking Technology Handbook (http:/ / docwiki. cisco. com/ wiki/
Internetworking_Technology_Handbook)
• Collection of animations and videos concerning computer networks (http:/ / www. khurramtanvir. com/
cs460demos. php)
Internet Protocol
The Internet Protocol (IP) is the principal communications protocol used for relaying datagrams (also known as
network packets) across an internetwork using the Internet Protocol Suite. Responsible for routing packets across
network boundaries, it is the primary protocol that establishes the Internet.
IP is the primary protocol in the Internet Layer of the Internet Protocol Suite and has the task of delivering datagrams
from the source host to the destination host solely based on the addresses. For this purpose, IP defines datagram
structures that encapsulate the data to be delivered. It also defines addressing methods that are used to label the
datagram source and destination.
Historically, IP was the connectionless datagram service in the original Transmission Control Program introduced by
Vint Cerf and Bob Kahn in 1974, the other being the connection-oriented Transmission Control Protocol (TCP). The
Internet Protocol Suite is therefore often referred to as TCP/IP.
The first major version of IP, Internet Protocol Version 4 (IPv4), is the dominant protocol of the internet. Its
successor is Internet Protocol Version 6 (IPv6), which is increasing in use.
Function
The Internet Protocol is responsible for addressing hosts and routing datagrams (packets) from a source host to the
destination host across one or more IP networks. For this purpose the Internet Protocol defines an addressing system
that has two functions: identifying hosts and providing a logical location service. This is accomplished by defining
standard datagrams and a standard addressing system.
Datagram construction
Each datagram has two components, a header and a
payload. The IP header is tagged with the source IP
address, destination IP address, and other meta-data
needed to route and deliver the datagram. The
payload is the data to be transported. This process of
nesting data payloads in a packet with a header is
called encapsulation.
IP addressing and routing
Perhaps the most complex aspects of IP are IP
addressing and routing. Addressing refers to how end
hosts are assigned IP addresses and how subnetworks
of IP host addresses are divided and grouped. IP
Sample encapsulation of application data from UDP to a Link protocol
routing is performed by all hosts, but most importantly by routers, which typically use either interior gateway
protocols (IGPs) or external gateway protocols (EGPs) to decide how to move datagrams among networks.
frame