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System Test Architecture Reference Manual for IP Telephony
OL-11591-01
Chapter12 IP Video Telephony Configuration
Cisco Unified CallManager Configuration for IP Video Telephony
The regions include the following devices:
•Region A (Video)—All video enabled phones, including Cisco Unified Video Advantage
•Region B (SJC-Local)—All devices without video capabilities
•Region C (SJC-WAN)—All intercluster trunks
•Region D (DFW-WAN)—All intercluster trunks
•Region E (DFW-Local)—All devices without video capabilities
Table12-22 shows the regions matrix for SJC.
Table12-23 shows the regions matrix for DFW.
When an H.323 video endpoint in Region A calls through an intercluster trunk in Region B, only the
G.711 codec is sent from SJC to DFW during the capabilities exchange process.
Thecall will arrive at DFW through an intercluster trunk in Region C and will then be routed to a device
in Region D. Only the G.729 codec will be sent from DFW to SJC during the capabilities exchange
process.
After the capabilities exchange process completes, the call will connect using the G.729 codec.
TheCisco Unified CallManager at SJC will invoke a transcoder between the H.323 video device and the
intercluster trunk. The transcoder will transcode the call between the G.729 and the G.711 codecs.
Transcoders and Call Transfer
This section provides an overview of a call-transfer scenario that involves a legacy transcoder.
Note Ciscolegacy transcoders (6608, CMM ACT, NM-HDV) currently do not support video pass-through. If
a video call is sent through a transcoder, the call will become an audio-only call.
Before the call is transferred in this scenario, it proceeds as described for Scenario 2 in the “SIP Trunk
Calls with Asymmetric Regions” section on page 12-19. That is, an H.323 video endpoint with only
G.711 capabilities in Region A calls a device in Region E through an intercluster trunk.
Afterthe call is established, it is transferred by the device in Region E to a local video endpoint in Region
F In this call-forward scenario, the call proceeds as follows:
Table12-22 SJC Regions Matrix
Region A Region B Region C
Region A G.711/384 G.711/384 G.711/384
Region B G.711/384 G.711/384 G.729/384
Region C G.711/384 G.729/384 G.729/384
Table12-23 DFW Regions Matrix
Region D Region E
Region D G.729/384 G.729/384
Region E G.729/384 G.711/384