In this article, we'll begin with the Internet Protocol, which is the protocol of the Internet. We'll also briefly introduce Version 6 of IP, also called IP Next Generation, which will replace IP Version 4 as the protocol of the Internet in the future. It's widely used in networking literature and is used to describe the position of a particular protocol or service in relation to other building blocks of networks. Figure A shows the OSI Model. An example of OSI communications between two computer systems in a routed internetwork.
Upper layers depend on lower layers to provide their functions.
The Internet Protocol lies at the network level. It depends on the levels below it, the data and physical levels, and provides services to the upper levels. As a protocol, IP is a connectionless and best-effort delivery protocol. Every IP packet has its own header, which essentially defines the packet. This defines the abstract type of service that, if possible, should be applied to this packet.