Cisco Cisco TelePresence Video Communication Server Expressway
Appendix 5 – Known interoperating limitations
Cisco VCS Deployment Guide: Microsoft OCS 2007 R2, Lync 2010 and Cisco VCS X7.0
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Upspeeding from a voice call to a video call
Interworking a MOC/Lync client to an H.323 endpoint, the call will only upspeed from voice to video if
the upspeed request occurs before the endpoint sends a BRQ lowering the connection bandwidth.
the upspeed request occurs before the endpoint sends a BRQ lowering the connection bandwidth.
Microsoft Mediation Server
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.
be configured into Cisco VCS.
B2BUA
Configure the “OCS/Lync gateway” VCS with a second zone to “To Microsoft OCS/Lync server via
B2BUA”, 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 “To Microsoft
OCS/Lync server via B2BUA
B2BUA”, 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 “To Microsoft
OCS/Lync server via B2BUA
Non-B2BUA
Configure the “OCS/Lync gateway” VCS with a second zone to OCS/Lync, 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 set Searches are automatically
responded to 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.
profile, select the same options as would be selected if the Microsoft Office Communications
Server 2007 zone profile had been selected and in addition set Searches are automatically
responded to 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.
VCS cluster calls to endpoints not registered using
FindMe – such as MCU calls where MCU is in its own
dedicated domain
FindMe – such as MCU calls where MCU is in its own
dedicated domain
OCS/Lync does not have a way of load balancing calls to a cluster of Cisco VCSs.
OCS
There is no way to tell OCS that there are multiple peers to receive calls for the 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 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 VCS clusters with OCS without B2BUA FindMe registration therefore provides resilience, not
extra capacity / load balancing.
extra capacity / load balancing.
Lync
Lync does not support DNS SRV, but it does allow the DNS record to be a Round-Robin record listing
all VCSs in the “OCS/Lync gateway” cluster./ Lync seems to continue to use just a single VCS until it
loses connectivity to that VCS. At that time it will choose a different VCS from the Round-Robin DNS
record.
all VCSs in the “OCS/Lync gateway” cluster./ Lync seems to continue to use just a single VCS until it
loses connectivity to that VCS. At that time it will choose a different VCS from the Round-Robin DNS
record.