Manual

Appendix 1 - Troubleshooting
One way media: MOC  endpoint registered to Cisco VCS
When using Microsoft Edge Server
When MOC registers to OCS through a Microsoft Edge Server, the local IP address and port that the
MOC declares are usually private and un-routable (assuming that MOC is behind a firewall and not
registered on a public IP address). In order to identify alternate addresses to route media to, the MOC
uses ICE candidates.
Handling MOC ICE candidates is not supported in Cisco VCS up to and including Cisco VCS X5.
Calls should connect OK, and media should flow from MOC to the video endpoint. Audio and video
from the endpoint are unlikely to be received by MOC, because the destination information is encoded
in the MOC ICE candidate lines.
When using a Hardware Load Balancer in front of OCS
Cisco VCS modifies the application part of INVITEs / OKs received from MOC to make them
compatible with traditional SIP SDP messaging. Cisco VCS only does this when it knows that the call
is with OCS. If there are problems with one-way media (media only going from MOC to the Cisco VCS
registered endpoint), check the Search history and ensure that the call is seen coming from an OCS
neighbor zone.
If it is not, then the call may be coming from a FEP rather than the load balancer. See the section on
configuring Cisco VCS and Hardware Load Balancers, and set up the relevant neighbor zones without
any associated search rules, but with Peer addresses containing the FEP IPs.
OCS rejects Cisco VCS zone alive OPTIONS checks with
‘401 Unauthorized’ and INFO messages with
‘400 Missing Correct Via Header'
 A response ‘400 Missing Correct Via Header’ is an indication that OCS doesn’t trust the sender of
the message.
 A response ‘401 Unauthorized’ response to OPTIONS is another indication that OCS doesn’t trust
the sender of the OPTIONS message.
Ensure that the Cisco VCS sending these message is included in the OCS’s Front End Processors >
Host Authorization list.
Note, this can be seen if a load balancer is used in front of the OCS, and OCS is configured with the
Host Authorization authorizing the Cisco VCS – OCS sees calls coming from the hardware load
balancer rather than from the Cisco VCS. See Appendix 13 – Cisco VCS and hardware load
balan
cers.
MOC stays in ‘Connecting …’ state
MOC does not change into the connected state until it receives RTP (media) from the device it is
connecting to.
No audio on audio call through an ISDN gateway
 Upgrade Cisco TelePresence ISDN GW to version 1.5.
Prior to version 1.5 the 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.
Cisco VCS Deployment Guide: Microsoft OCS 2007 R1 and R2 and Cisco VCS X5.2 Page 67 of 92