Cisco 7604 Configuration Manual page 482

MGCP Inspection
Figure 22-11
Gateway is told
to send its media
to
(public address
of the IP Phone)
MGCP endpoints are physical or virtual sources and destinations for data. Media gateways contain
endpoints on which the call agent can create, modify and delete connections to establish and control
media sessions with other multimedia endpoints. Also, the call agent can instruct the endpoints to detect
certain events and generate signals. The endpoints automatically communicate changes in service state
to the call agent.
MGCP transactions are composed of a command and a mandatory response. There are eight types of
commands.
CreateConnection
•
ModifyConnection
•
DeleteConnection
•
NotificationRequest
•
• Notify
• AuditEndpoint
• AuditConnection
RestartInProgress
•
The first four commands are sent by the call agent to the gateway. The Notify command is sent by the
gateway to the call agent. The gateway may also send a DeleteConnection command. The registration of
the MGCP gateway with the call agent is achieved by the RestartInProgress command. The
AuditEndpoint and the AuditConnection commands are sent by the call agent to the gateway.
All commands are composed of a Command header, optionally followed by a session description. All
responses are composed of a Response header, optionally followed by a session description.
To use MGCP, you usually need to configure inspection for traffic sent to two ports:
Catalyst 6500 Series Switch and Cisco 7600 Series Router Firewall Services Module Configuration Guide using ASDM
22-66
Using NAT with MGCP
To PSTN
Cisco
PGW 2200
209.165.201.11
MGCP
209.165.200.231
209.165.200.231
Chapter 22
H.323
209.165.201.1
SCCP
GW
GW
RTP to 209.165.201.1
from 209.165.200.231
Applying Application Layer Protocol Inspection
M
Cisco
M
CallManager
M
209.165.201.10
209.165.200.231
RTP to 10.0.0.76
from 209.165.200.231
IP IP IP
10.0.0.76
Branch offices
OL-20748-01