Internet Protocol

UDP encapsulation

TCP and IP protocols development timeline-en

First Internet Demonstration, 1977

Internet Protocol (IP) is the principal communications protocol in the Internet protocol suite for relaying datagrams across network boundaries. Its routing function enables internetworking, and essentially establishes the Internet. IP has the task of delivering packets from the source host to the destination host solely based on the IP addresses in the packet headers. For this purpose, IP defines packet structures that encapsulate the data to be delivered. It also defines addressing methods that are used to label the datagram with source and destination information.

Overview

The Internet Protocol is designed for use in interconnected systems of packet-switched computer communication networks. The protocol is used to communicate across the Internet by identifying both the initiating and receiving network addresses. IP is a network layer protocol in the OSI model and facilitates the transfer of data between devices on different networks.

Functionality

IP provides an unreliable, connectionless service to the upper layer protocols. This means that IP does not guarantee the delivery of packets, nor does it ensure that packets are delivered in the same order in which they were sent. The Internet Protocol only provides a basic service with the aim of transferring packets from a source to a destination over an interconnected system of networks.

IP Versions

There are two versions of Internet Protocol currently in use, IPv4 and IPv6.

• IPv4 is the fourth version of IP. It is the first version of the protocol to be widely deployed, and forms the basis for most of the Internet's current architecture. IPv4 addresses are 32 bits long, limiting the address space to 4.3 billion unique addresses.

• IPv6 was developed to deal with the long-anticipated problem of IPv4 address exhaustion. IPv6 addresses are 128 bits long, significantly increasing the address space to accommodate the growing number of devices connected to the Internet.

Addressing

IP addressing entails assigning an IP address to each device on a network. The address identifies the host and its network interface, and is used for routing traffic across the Internet. IP addresses are binary numbers but are typically expressed in human-readable notations, such as dotted decimal for IPv4 or hexadecimal for IPv6.

IP Datagram

An IP datagram is a packet of data that includes not just the payload (the data being transmitted) but also header information that IP uses to get the datagram to its destination. The IP header includes various fields such as the version number, source and destination IP addresses, and the time to live (TTL) which helps in preventing datagrams from circulating indefinitely.

Routing

IP routing is the process of transporting packets from a source to a destination across multiple IP networks. Routers perform the traffic directing functions on the Internet. A packet's route to its destination is determined by the routing tables maintained in each router along the path.

Security

The basic design of the Internet Protocol does not include robust mechanisms for ensuring the security and integrity of communications. This has led to the development of additional protocols such as IPsec for securing IP communications by authenticating and encrypting each IP packet of a communication session.

Conclusion

The Internet Protocol is a fundamental element in the infrastructure of the modern Internet, enabling diverse and geographically dispersed networks to communicate. Despite its simplicity, IP plays a crucial role in the delivery of data across digital networks.