Cisco PIX 500 Series Configuration Manual page 519

Chapter 25 Configuring Application Layer Protocol Inspection
Figure 25-4
Gateway is told
to send its media
to 209.165.200.231
(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. 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.
The port on which the gateway receives commands from the call agent. Gateways usually listen to
•
UDP port 2427.
OL-12172-03
Using NAT with MGCP
To PSTN
Cisco
PGW 2200
209.165.201.11
MGCP
209.165.200.231
GW
RTP to 209.165.201.1
from
H.323
M
209.165.201.10
209.165.201.1
SCCP
GW
209.165.200.231
Cisco Security Appliance Command Line Configuration Guide
MGCP Inspection
M
Cisco
M
CallManager
209.165.200.231
RTP to 10.0.0.76
from 209.165.200.231
IP IP IP
10.0.0.76
Branch offices
25-55