Fundamentals of Communications and Networking, 3rd Edition

TCP/IP Reference Model

An alternative to the OSI model is the Transmission Control Protocol/Internet Protocol (TCP/IP) Reference Model, which defines four layers as opposed to the seven layers in the OSI model. The TCP/IP model represents the same functionality as the OSI model, but several of the OSI layers are combined to create a streamlined model. The simplified model maps well to the backbone of Internet communications, the TCP/IP protocol suite. The biggest difference between the two models is in each model’s purpose. Although they are often used somewhat interchangeably, they address different needs. The OSI Reference Model was originally published as a prescriptive model. The OSI Reference Model provides a prescription as to how organizations ...