Monday, March 19, 2012

Troubleshooting of IBM Sametime-Polycom integration: SIP 503 error

I just want to share with you an experience of troubleshooting. For a TCSPI-based IBM Sametime-Polycom integration, I have encountered this error :

The call was not completed due to a dialing error.
.................................................................
AVKCS2200E: Failure response 503 received in response to invitation to CN=Vincent Perrin,CN=Users,DC=polycomlive,DC=com.  Reason is: Unspecified Dial Failure




SIP Error 503 means according RFC 3261: Service Unavailable - The server is temporarily unable to process the request due to a temporary overloading or maintenance of the server.

For a further investigation, I have activated more detailled logs on the Sametime Media Manager
*=info: com.ibm.telephony.conferencing.plcmav.*=all
To activate that new level of logs, please read that documentation (here).

The Polycom TCSPI worked perfectly, the conference was created on the Polycom RMX, but I have found that error in the log.

Unexpected response code 503 for SIP INVITE for SIP ConferenceId TCSPI_ID=[61]com.ibm.telephony.conferencing.plcmav.PlcmAVConferenceService/91126 and SIP user sip:91126@10.252.77.57

And that SIP invite from the IBM Sametime Connect Client to the Polycom RMX conference ID (in my case 91126):

SIP/2.0 503 Service Unavailable
Call-ID: 7233800890847192@10.253.83.37
CSeq: 2 INVITE
From: <sip:vincent.perrin%40polycom.com@media.ibmuc.lab;placeid=70c545ba-6e48-4d27-8940-0573652116e7;endpoint=mcu>;tag=06650845904496405_local.1332145605791_13_29
To: <sip:91126@10.252.77.57>
Via: SIP/2.0/TCP media.ibmuc.lab:5060;rport;ibmsid=local.1332145605791_13_29;branch=z9hG4bK311714849499946
Content-Length: 0


So, why the service is unavailable ?
  • SIP enable or not ? SIP has been enable on the RMX as described in "Polycom® Unified Communications Deployment Guide for IBM® Sametime® Environments" at page 27.
  • SIP Transport ? Bingo... TLS has been enabled :(
To solve that issue:
In the RMX Management pane, click IP Network Services, go to SIP servers, change Transport Type from TLS to TCP... and restart the RMX.


After the restart of the RMX, I did a test in a Sametime Meeting room to validate the configuration.
Now, everything works fine !!!


Hope that entry will help you to solve this potential issue on your future IBM/Polycom integration...