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Cisco ASA 5500 Series Configuration Guide using the CLI
Chapter44 Configuring Inspection for Voice and Video Protocols
MGCP Inspection
•The port on which the call agent receives commands from the gateway. Call agents usually listen to
UDP port 2727.
Note MGCP inspection does not support the use of different IP addresses for MGCP signaling and RTP data.
A common and recommended practice is to send RTP data from a resilient IP address, such as a loopback
or virtual IP address; however, the ASA requires the RTP data to come from the same address as MGCP
signalling.
Configuring an MGCP Inspection Policy Map for Additional Inspection Control
If the network has multiple call agents and gateways for which the ASA has to open pinholes, create an
MGCP map. You can then apply the MGCP map when you enable MGCP inspection.
To create an MGCP map, perform the following steps:
Step1 To create an MGCP inspection policy map, enter the following command:
hostname(config)# policy-map type inspect mgcp map_name
hostname(config-pmap)#
Where the policy_map_name is the name of the policy map. The CLI enters policy-map configuration
mode.
Step2 (Optional) To add a description to the policy map, enter the following command:
hostname(config-pmap)# description string
Step3 To configure parameters that affect the inspection engine, perform the following steps:
a. To enter parameters configuration mode, enter the following command:
hostname(config-pmap)# parameters
hostname(config-pmap-p)#
b. To configure the call agents, enter the following command for each call agent:
hostname(config-pmap-p)# call-agent ip_address group_id
Use the call-agent command to specify a group of call agents that can manage one or more gateways.
The call agent group information is used to open connections for the call agents in the group (other
than the one a gateway sends a command to) so that any of the call agents can send the response.
call agents with the same group_id belong to the same group. A call agent may belong to more than
one group. The group_id option is a number from 0 to 4294967295. The ip_address option specifies
the IP address of the call agent.
Note MGCP call agents send AUEP messages to determine if MGCP end points are present. This
establishes a flow through the ASA and allows MGCP end points to register with the call agent.
c. To configure the gateways, enter the following command for each gateway:
hostname(config-pmap-p)# gateway ip_address group_id
Use the gateway command to specify which group of call agents are managing a particular gateway.
The IP address of the gateway is specified with the ip_address option. The group_id option is a
number from 0 to 4294967295 that must correspond with the group_id of the call agents that are
managing the gateway. A gateway may only belong to one group.