This protocol facilitates the exchange of information between Media Gateway and Media Gateway Controller(MGC).
MGCP is a master slave protocol in which controllers, known as call agents, Control the operation of media gateways. The call agent commands generally relate to the establishment of connections and teardown of connections from one side of gateway to another.
MGCP only address the communication between a call agent and a media gateway and doesnot address communication from one call agent to anther.
MGCP End point:
1. DSO Channel: A digital channel operation at 64 kbps. This channel is multiplexed with a larger transmission facility like DS1 1.54 Mbps, E1 2.048 Mbps. DSO will carry voice that is coded according to G.711
2. Analog Line: Typically this endpoint that interfaces to a standard telephone line and provides service to a traditional telephone.
3. IVR (Interactive Voice Response): An endpoint provides access to an IVR system, where prompts and announcements can be played.
4. Conference Bridge Access Point: An endpoint where media streams from multiple callers can be mixed.
5. Packet Relay: A specific form of conference bridge supporting only two connections. This type of endpoint will use packet transport on both connections.
6. Wiretop Access Point: A point form, which connection is made to another endpoint for the purpose of listing to the media transmitted (or) received at that end point. This connection is one way only.
7. Asynchronous Transfer Mode (ATM): An endpoint corresponding to the termination of an ATM Trunk, where such a trunk might be an ATM virtual circuit.
8. Announcement Server access point: An endpoint providing access to a single announcement Normally a connection to this type of endpoint will be one way.
1. One endpoint can associated 1024 connections theritically, but 512 connections practically.
2. PBX can handle upto 500 calls/min.
3. Blade server can handle upto 10000-100000 calls/min.
MGCP defines nine commands , some of which are sent from the call agemt to the gateway and some from gateway to the call agent . MGCP commands are composed of a command line, a number of parameter lines and optionally a SDP.
Syntx : command (space) Transaction ID (space) endpoints (space) MGCP 1.0
1. EPCF (endpoint configuration): Issued by a call agent to a gateway in order to inform the gateway about bearer/coding characteristics on the line side of one or more endpoints. (MGC-MG)
2. CRCX (create connection): Used to create connection at endpoint (MGC-MG)
3.MDCX ( Modify connection): To change some characteristics of an existing connection (MGC-MG)