The assets of the protocol Port Control Protocol (PCP)

Both the global IPv4 address depletion and the subsequent multiplication of middleboxes like Network Address Translators in the Internet dramatically complicate everyday network management operations, let alone the risk of seriously degrading service performances.

The Port Control Protocol (PCP) that was recently standardized by the Internet Engineering Task Force (IETF) is seen as one of the most attractive responses to this issue: PCP indeed relies upon a simple client/server architecture that aims at dynamically controlling the behavior of the aforementioned middleboxes. PCP is also very flexible from a functional evolution perspective, so that it becomes a de facto standard for the dynamic control of Internet resources. The protocol is designed to ease operating servers behind middleboxes and to optimize keep-alive messages that would severely impact some terminal devices such as mobile User Equipment (UE)..

This paper is an introduction to PCP: it details PCP design basics and operations,. The paper also illustrates typical PCP usage by means of flow charts.