The TCP/IP protocol model for internetwork communications was created in the early 1970s and is sometimes referred to as the Internet model. As shown in the figure, it defines four categories of functions that must occur for communications to be successful. The architecture of the TCP/IP protocol suite follows the structure of this model. Because of this, the Internet model is commonly referred to as the TCP/IP model.

Most protocol models describe a vendor-specific protocol stack. However, because the TCP/IP model is an open standard, one company does not control the definition of the model. The definitions of the standard and the TCP/IP protocols are discussed in a public forum and defined in a publicly available set of RFCs. The RFCs contain both the formal specification of data communications protocols and resources that describe the use of the protocols.

The RFCs also contain technical and organizational documents about the Internet, including the technical specifications and policy documents produced by the IETF.