48-2
Cisco ASA 5500 Series Configuration Guide using ASDM
Chapter48 Configuring Inspection for Voice and Video Protocols
H.323 Inspection

Limitations and Restrictions

The following summarizes limitations that apply when using CTIQBE application inspection:
•CTIQBE application inspection does not support configurations with the alias command.
•Stateful failover of CTIQBE calls is not supported.
•Debugging CTIQBE inspection may delay message transmission, which may have a performance
impact in a real-time environment. When you enable this debugging or logging and
Cisco IP SoftPhone seems unable to complete call setup through the ASA, increase the timeout
values in the Cisco TSP settings on the system running Cisco IP SoftPhone.
The following summarizes special considerations when using CTIQBE application inspection in specific
scenarios:
•If two Cisco IP SoftPhones are registered with different Cisco CallManagers, which are connected
to different interfaces of the ASA, calls between these two phones fails.
•When Cisco CallManager is located on the higher security interface compared to
Cisco IP SoftPhones, if NAT or outside NAT is required for the CiscoCallManager IP address, the
mapping must be static as Cisco IP SoftPhone requires the Cisco CallManager IP address to be
specified explicitly in its Cisco TSP configuration on the PC.
•When using PAT or Outside PAT, if the CiscoCallManager IP address is to be translated, its TCP
port 2748 must be statically mapped to the same port of the PAT (interface) address for Cisco IP
SoftPhone registrations to succeed. The CTIQBE listening port (TCP 2748) is fixed and is not
user-configurable on CiscoCallManager, Cisco IP SoftPhone, or Cisco TSP.
H.323 Inspection
This section describes the H.323 application inspection. This section includes the following topics:
•H.323 Inspection Overview, page48-3
•How H.323 Works, page48-3
•H.239 Support in H.245 Messages, page48-4
•Limitations and Restrictions, page48-4
•Select H.323 Map, page 48-5
•H.323 Class Map, page48-5
•Add/Edit H.323 Traffic Class Map, page48-6
•Add/Edit H.323 Match Criterion, page48-6
•H.323 Inspect Map, page 48-7
•Phone Number Filtering, page48-9
•Add/Edit H.323 Policy Map (Security Level), page48-9
•Add/Edit H.323 Policy Map (Details), page48-11
•Add/Edit HSI Group, page48-12
•Add/Edit H.323 Map, page48-13