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
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] and SIP user sip:91126@

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@
From: <;placeid=70c545ba-6e48-4d27-8940-0573652116e7;endpoint=mcu>;tag=06650845904496405_local.1332145605791_13_29
To: <sip:91126@>
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...