Mapping Network Protocols to Layers of the OSI Model

The 7-layer OSI architecture is the most important model for teaching computer networking. However, the various computer networking teaching sources contain much disagreement, if not outright argument, about which OSI layer describes the respective protocols used in today’s networks. If the academic claim is true that the OSI model completely describes computer networking, a consensus should be possible on where any network protocol is located in this model. Such consensus has not been achieved – Is there something wrong with the procedure of mapping network protocols to layers of the OSI model? This paper attempts to shed light on the issue by claiming that there are indeed three different sets of criteria for deciding which OSI layer governs what protocol. It describes them, shows how their amalgamation leads to consistency problems, and offers an outline of what OSI layer placement of common protocols they suggest if they are being followed consistently. It further considers the distinction between network protocols and network management protocols, refuting its ability to solve the problem. It concludes by recommending to consistently stick to one set of placement criteria.