Cisco Cisco TelePresence Video Communication Server Expressway
Appendix 1 – Troubleshooting
Cisco VCS Deployment Guide: Microsoft OCS 2007 R2, Lync 2010 and Cisco VCS X7.1
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From IP address
This is normally seen if the B2BUA forwards an INVITE from a standards-based video endpoint where
the ‘From’ header in the SIP INVITE only contains the IP address of the endpoint, e.g. “From:
<sip:10.10.2.1>;tag=d29350afae33”. This is usually caused by a misconfigured SIP URI in the
endpoint. In future versions of B2BUA, the “From”-header will be manipulated if necessary to avoid
this issue.
the ‘From’ header in the SIP INVITE only contains the IP address of the endpoint, e.g. “From:
<sip:10.10.2.1>;tag=d29350afae33”. This is usually caused by a misconfigured SIP URI in the
endpoint. In future versions of B2BUA, the “From”-header will be manipulated if necessary to avoid
this issue.
Encryption mismatch
Look for the reason for the 488. If it mentions encryption levels do not match, ensure that you have
configured encryption appropriately, either:
configured encryption appropriately, either:
“OCS/Lync gateway” VCS has enhanced collaboration option key included, or
OCS/Lync is configured such that encryption is supported (or set as “DoNotSupportEncryption”) –
note that if the encryption support is changed on OCS/Lync then a short time must be left for the
change to propagate through OCS/Lync server and then the MOC / Lync client must be signed off
and then signed back in again to pick up the new configuration.
note that if the encryption support is changed on OCS/Lync then a short time must be left for the
change to propagate through OCS/Lync server and then the MOC / Lync client must be signed off
and then signed back in again to pick up the new configuration.
Call connects but clears after about 30 seconds
If a call connects but shortly later clears, this is likely to be because the caller’s ACK response to the
200 OK is not being properly routed. To resolve this, make sure that the VCS and OCS/Lync servers
are able to resolve each other’s FQDNs In DNS.
200 OK is not being properly routed. To resolve this, make sure that the VCS and OCS/Lync servers
are able to resolve each other’s FQDNs In DNS.
Cisco VCS to OCS/Lync server calls fail – DNS server
Cisco VCS needs to have details about DNS names of OCS/Lync pools and servers, and therefore
needs to have one of its DNS entries set to point to a DNS server which can resolve the FQDNs of the
OCS/Lync pools and servers.
needs to have one of its DNS entries set to point to a DNS server which can resolve the FQDNs of the
OCS/Lync pools and servers.
Cisco VCS to OCS/Lync calls fail – Hardware Load Balancer
If the OCS/Lync environment has FEPs with an HLB in front, ensure that the Cisco VCS is neighbored
with the HLB. If it is neighbored with an FEP directly, trust for VCS will be with the FEP. VCS will send
call requests to the FEP, but the FEP will record-route the message such that the ACK response
should be sent to the HLB. The ACK sent to the HLB gets rejected by OCS/Lync server, so OCS/Lync
clears the call after the SIP timeout due to the FEP not seeing the ACK.
with the HLB. If it is neighbored with an FEP directly, trust for VCS will be with the FEP. VCS will send
call requests to the FEP, but the FEP will record-route the message such that the ACK response
should be sent to the HLB. The ACK sent to the HLB gets rejected by OCS/Lync server, so OCS/Lync
clears the call after the SIP timeout due to the FEP not seeing the ACK.
(Calls MOC/Lync client – registered to the FEP – to Cisco VCS may still work.)
Media problems in calls involving external MOC/Lync
clients connecting via an Edge server
clients connecting via an Edge server
RTP over TCP/UDP
The Edge server supports RTP media over both TCP and UDP, whereas the B2BUA and standards
based video endpoints only support RTP over UDP. The Edge server and any firewalls that the Edge
server may pass media traffic through may need to be reconfigured to allow RTP over UDP as well as
RTP over TCP to be passed.
based video endpoints only support RTP over UDP. The Edge server and any firewalls that the Edge
server may pass media traffic through may need to be reconfigured to allow RTP over UDP as well as
RTP over TCP to be passed.
ICE negotiation failure
This can usually be detected by the call clearing with a BYE with reason header “failed to get media
connectivity”.
connectivity”.