08-04-2009, 07:21 AM
This protocol controls telephony gateways from external call control elements called media gateway controllers or call agents. Converting among the audio signals carried on telephone circuits and data packets carried over the Internet or over other packet networks is done by telephony gateway. According to the call control architecture assumption of the MGCP the call control intelligence is outside the gateways and handled by external call control elements and these call control elements, or Call Agents, will synchronize with each other to send coherent commands to the gateways under their control.[para] Thus essentially MGCP is a master/slave protocol, where the gateways are expected to execute commands sent by the Call Agents. The MGCP implements the media gateway control interface as a set of transactions. The transactions are composed of a command and a mandatory response