Cisco Cisco TelePresence Video Communication Server Expressway
Appendix 4 – Known interoperating limitations
Microsoft Mediation Server
Using OCS R1
Calls to Microsoft Mediation Servers are not supported by Cisco VCS.
Using OCS R2
Calls to Microsoft Mediation Servers work from endpoints in the Cisco VCS Video Network for SIP
initiated calls, but do not work for interworked H.323 initiated calls (the mediation server does not
respond to the Cisco VCS INFO message, sent to check availability of the destination number).
initiated calls, but do not work for interworked H.323 initiated calls (the mediation server does not
respond to the Cisco VCS INFO message, sent to check availability of the destination number).
A workaround is possible if the format of the numbers that will be routed to the mediation server can
be configured into Cisco VCS: make a second zone to OCS, select the Custom Zone profile, select
the same options as would be selected if the Microsoft Office Communications Server 2007 Zone
profile had been selected and in addition select ‘Searches are automatically responded to’=On. Then
configure one or more Search rules so that calls destined for the mediation server are routed to this
zone rather than to the standard Microsoft Office Communications Server 2007 zone.
be configured into Cisco VCS: make a second zone to OCS, select the Custom Zone profile, select
the same options as would be selected if the Microsoft Office Communications Server 2007 Zone
profile had been selected and in addition select ‘Searches are automatically responded to’=On. Then
configure one or more Search rules so that calls destined for the mediation server are routed to this
zone rather than to the standard Microsoft Office Communications Server 2007 zone.
Cisco VCS Cluster without OCS Relay
OCS does not have a way of load balancing calls to a cluster of Cisco VCSs. There is no way to tell
OCS that there are multiple peers to receive calls for the Cisco VCS domain, and OCS will not load
balance on a DNS SRV record, and there is a limit in OCS (and Windows) that the min TTL on Round
Robin DNS is 5 minutes.
OCS that there are multiple peers to receive calls for the Cisco VCS domain, and OCS will not load
balance on a DNS SRV record, and there is a limit in OCS (and Windows) that the min TTL on Round
Robin DNS is 5 minutes.
Use of Cisco VCS clusters with OCS and without OCS Relay therefore provides resilience, not extra
capacity.
capacity.
No audio on audio call through an ISDN gateway
Prior to version 1.5 the Cisco TelePresence ISDN GW sent RTP traffic from SSRC = 0; MOC would
not accept RTP traffic with SSRC = 0. From version 1.5 the ISDN GW sends RTP traffic from a
random, non zero, SSRC and MOC receives this correctly.
not accept RTP traffic with SSRC = 0. From version 1.5 the ISDN GW sends RTP traffic from a
random, non zero, SSRC and MOC receives this correctly.
No video through an ISDN gateway
Prior to X5 there was an issue with ISDN endpoints that initiated a call using one set of codecs, then
before sending media, changed the codecs to “better” codecs (for example, an initial offering of H.261
updated to H.263). Neither MOC R1, nor MOC R2 accepts a change in codec before media is sent.
before sending media, changed the codecs to “better” codecs (for example, an initial offering of H.261
updated to H.263). Neither MOC R1, nor MOC R2 accepts a change in codec before media is sent.
In X5 Cisco VCS delays sending the original capabilities for 7 seconds to wait and see if they will get
updated.
updated.
MOC receives no video if it holds and then resumes a call
MOC does not request fast picture updates and so unless full frames are automatically sent from time
to time by endpoints this results in no video on the MOC.
to time by endpoints this results in no video on the MOC.
Video will be seen by MOC when using:
MXP F8.0 or later SIP - as this supports the auto-generation of full video frames
Cisco VCS X4.2 or later for calls interworked with H.323 endpoints – as Cisco VCS interworking
supports the auto-generation of full frame update requests.
supports the auto-generation of full frame update requests.
Even with these fixes, sometimes MOC complains that it has no audio device configured when
selecting resume … follow MOC’s instructions to update the audio device and resume will then work.
selecting resume … follow MOC’s instructions to update the audio device and resume will then work.
Cisco VCS Deployment Guide: Microsoft OCS 2007 R1 and R2 and Cisco VCS X5.2
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