||The English used in this article may not be easy for everybody to understand. (April 2012)|
The TCP/IP model (Transmission Control Protocol/Internet Protocol) is a descriptive framework for the Internet Protocol Suite of computer network protocols. DARPA, an agency of the United States Department of Defense, created it in the 1970s. It evolved from ARPANET, which was an early wide area network and a predecessor of the Internet. The TCP/IP Model is sometimes called the Internet Model or less often the DoD Model.
The TCP/IP model describes a set of general design guidelines and implementations of specific networking protocols to enable computers to communicate over a network. TCP/IP provides end-to-end connectivity specifying how data should be formatted, addressed, transmitted, routed and received at the destination. Protocols exist for a variety of different types of communication services between computers.
TCP/IP has four abstraction layers as defined in RFC 1122. People often compare this layer architecture with the seven-layer OSI Reference Model; using terms such as Internet reference model. This is incorrect, however, because it is descriptive while the OSI Reference Model was intended to be prescriptive, hence being a reference model.
The TCP/IP model and related protocols are maintained by the Internet Engineering Task Force (IETF).