MGCP Overview
MGCP is a agreement acclimated aural a broadcast VoIP system. MGCP is authentic in RFC
3435, which obsoletes an beforehand analogue in RFC 2705. Another agreement acclimated for the
same purpose is Megaco, a coproduction of Internet Engineering Task Force (IETF) (RFC
3525) and ITU (Recommendation H.248-1). Both protocols chase the guidelines of the
API Media Aperture Ascendancy Agreement Architecture and Requirements at RFC 2805.
These IETF standards alarm MGCP as a centralized accessory ascendancy agreement with simple
endpoints. The MGCP agreement allows a axial ascendancy component, or alarm agent, to
remotely ascendancy assorted devices. This agreement is referred to as a bang protocol
because the endpoints and gateways cannot action alone. MGCP incorporates the
IETF Affair Description Agreement (SDP) to alarm the blazon of affair to initiate.
MGCP is an addendum of the beforehand adaptation of Simple Aperture Ascendancy Agreement (SGCP)
and supports SGCP functionality in accession to several enhancements. Systems using
SGCP can calmly drift to MGCP, and MGCP commands are accessible to accredit SGCP
capabilities.
MGCP is a plaintext agreement that uses a server-to-client accord amid the call
agent and the aperture to absolutely ascendancy the aperture and its associated ports. The plaintext
commands are beatific to gateways from the alarm abettor application UDP anchorage 2427. Anchorage 2727 is
used to accelerate letters from the gateways to the alarm agent.
An MGCP aperture handles adaptation amid audio signals and a packet network.
Gateways collaborate with a alarm abettor (CA), additionally alleged a Media Aperture Controller (MGC),
that performs arresting and alarm processing on aperture calls. In the MGCP configurations
that Cisco IOS supports, a aperture can be a Cisco router, admission server, or cable modem,
and the CA is a server from a third-party vendor.
Configuration commands for MGCP ascertain the aisle amid the alarm abettor and the gateway,
the blazon of gateway, and the blazon of calls handled by the gateway.
MGCP uses endpoints and access to assemble a call. Endpoints are sources or destinations
for abstracts and can be concrete or analytic locations in a device. Access can be
point-to-point or multipoint.
Similar to SGCP, MGCP uses UDP for establishing audio access over IP networks.
However, MGCP additionally uses “hairpinning” to acknowledgment a alarm to the PSTN back the packet
network is not available.