The Media Gateway Control Protocol (MGCP) is an implementation of the Media Gateway Control Protocol architecture for controlling media gateways on Internet Protocol (IP) networks connected to the public switched telephone network (PSTN).

MGCP is a text-based signaling and call control communications protocol used in Voice over IP (VoIP) systems. It implements a model similar to the structure of the PSTN with the power of the network residing in a call control center softswitch which is analogous to the central office in the telephone networks. The endpoints are low-intelligence devices, mostly executing control commands.

MGCP uses the Session Description Protocol (SDP) for specifying and negotiating the media streams to be transmitted in a call session and the Real-time Transport Protocol (RTP) for framing of the media streams.

Typically, a Media Gateway is configured with a list of Call Agents from which it may accept programming (where that list normally comprises only one or two Call Agents). MGCP assumes that the multiple Call Agents will maintain knowledge of device state among themselves (presumably with an unspecified protocol) or rebuild it if necessary (in the face of catastrophic failure). Its failover features take into account both planned and unplanned outages.