media gateway control protocol (MGCP)
The MediaGateway Control Protocol (MGCP) is an open gateway protocol proposed for standardization by Level 3 and Telecordia and published as informational by the Internet Engineering Task Force( IETF), but not standardized. MGCP evolved from IP Device Control( IPDC) and Simple Gateway Control Protocol( SGCP) and is described in RFC 2705 and 3435.
MGCP converts audio signals from the public switched telephone network into data packets for transport over the Internet. This ensures communication between media gateway controllers( MGC) and media gateways( MGW). There are eight different command types for communication between Media Gateway Controllers (MGC) and the Media Gateways (MGW). The MGCP protocol combines the IPDC and SGCP protocols.
MGCP allows media gateways to be monitored by external control stations, the media gateway controllers or call agents. For session establishment, MGCP uses the Session Announcement Protocol( SAP), the Session Initiation Protocol( SIP), and the Realtime Streaming Protocol( RTSP).
Because the MGCP architecture leaves all call control to external monitoring elements or agents, these functions no longer need to be integrated into the gateways. The MGCP protocol became less important with the advent of MEGACO/H.248.