There are two architectural models commonly used to describe the internetworking protocols and methods. The first one is Open System Interconnection (OSI) reference model developed under the auspices of the International Organization for Standardization (ISO). It provides a rigorous description for layering protocol functions from the underlying hardware to the software interface concepts in user applications. Internetworking is implemented in Layer 3 (the network layer) of the model.

The Internet Protocol Suite is the second model (also known as TCP/IP). It is named from two of the most important protocols in it: the Transmission Control Protocol (TCP) and the Internet Protocol (IP), which were the first two networking protocols defined in this standard.

The Internet Protocol Suite, like many protocol suites, may be viewed as a set of layers. Each layer solves a set of problems involving the transmission of data, and provides a well-defined service to the upper layer protocols based on using services from some lower layers. Upper layers are logically closer to the user and deal with more abstract data, relying on lower layer protocols to translate data into forms that can eventually be physically transmitted.

1 OSI Model
2 Internet Protocol Suite