Question : OCS 2007 R2 problems adding pstn users via sip trunk to pc audio conference

Dear all,

We're using OCS 2007 R2 on Server 2008, we have standard edition servers installed for front end, an edge server and a mediation server. All users are using the R2 client, we do not have pbx integration.

Our mediation server has only one nic.

We have enterprise voice enabled with a sip trunk from interouteone, it seems to work very well after some initial issues with a Checkpoint firewalls interpretation of the call setup procedure. We can dial out and voice quality is great. Our problems come when establishing conferences between pc audio clients and pstn clients.

If i call a PSTN user first, i can subsequently succesfully, add internal, communicator/pc audio clients to a conference with the pstn user.

If i call a communicator/pc audio client first i cannot subsequently add a pstn user to the conference, when i do this i receive "An error occurred during the call. More Details (ID:404) in communicator

If i snoop the S4 logs on the mediation server I see

SIP/2.0 404 Not Found both in and outbound.

and:

Ms-diagnostics: 10404;source="mymediationserver.atmycompany.net";reason="Gateway returned a SIP failure code";component="MediationServer";SipResponseCode="404";SipResponseText="Not Found";GatewayFqdn="89.202.*.*"

My interpretation of this is that this is an error from my SIP trunk providers gateway? However i find that difficult to believe as they provide this service to hundreds of companies and i expect the issue is more down to my misconfiguration.....

Is this due to a difference in the way conference calls are dialled as compared to normal calls? Perhaps a number translation issue?

If i examine my communicator logs i see this when i try to add the external pstn user to the conference already in progress: SIP/2.0 481 Call Leg/Transaction Does Not Exist.

I suspect this is closely related as sounds very similar: http://social.microsoft.com/Forums/en-US/communicationsservertelephony/thread/3583bae8-ef28-41d8-9108-66e0df6bc814?prof=required but i don't have the first clue regarding adding number translations for conference calls, my current translation is the one i was instructed to set up by interoute.

Any guidance appreciated.

Best,

Jim.

Answer : OCS 2007 R2 problems adding pstn users via sip trunk to pc audio conference

HI there, it appears that it's not a problem on our side at all, but the gateway providers pre-paid platform will not allow conferencing with pstn calls, it's a fault rather than a disabled feature. We are moving to post paid and that will apparently resolve this.

Cheers for the help and suggestions,

Jim