Cisco Cisco TelePresence Video Communication Server Expressway
Appendix 1 – Troubleshooting
Cisco VCS Deployment Guide: CUCM v6.1, 7 and 8 with Cisco VCS X7 using a SIP trunk
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a SIP call to CUCM and CUCM sends the ‘422 Session Timer too small’ message Cisco VCS clears
the call.
the call.
From X5.0, setting the neighbor zone to “Cisco Unified Communications Manager” enables Cisco VCS
to handle session timer exchanges with CUCM, and so the changes to configuration in CUCM
documented below should be unnecessary.
to handle session timer exchanges with CUCM, and so the changes to configuration in CUCM
documented below should be unnecessary.
For X4.x and earlier versions of Cisco VCS code, the workaround is to set CUCM to support a
Minimum Session Expires time that matches that requested by endpoints.
Minimum Session Expires time that matches that requested by endpoints.
Video endpoints typically request a Session-Expires: 500 and CUCM has a default Min-SE (Minimum
Session Expires): 1800
Session Expires): 1800
To configure CUCM to have a Minimum Session Expires time <= 500:
1. Go to
System > Service Parameters
.
2. Select Server = current server, for example “<IP> (Active)”.
3. Select Service = Cisco CallManager (Active).
4. Search for SIP Min-SE Value and set it to 500.
5. Click Save.
Cisco VCS reports SIP decode error
CUCM 5 and 6
When CUCM is not configured to connect to Cisco VCS, CUCM responds to the OPTIONS pings that
Cisco VCS sends to it with a 503 “Service unavailable”.
Cisco VCS sends to it with a 503 “Service unavailable”.
The 503 message contains a warn header which should be constructed as:
“Warning” 3 digit warn code <space> warn agent <space> warn text
“Warning” 3 digit warn code <space> warn agent <space> warn text
CUCM wrongly misses out the warn agent.
The 503 message contains a warn header which has a text section opened by “ and closed by ‘.
Both open and close should be “.
Both open and close should be “.
Cisco VCS rightfully reports this as an illegal construct.