SIP Gateway to PSTN Marked Unavailable RRS feed

  • Question

  • All,

    I have an issue where my PSTN gateway is marked as unavailable. At present the Mediation servers can see the PSTN gateway after a Mediation service restart, so inbound and outbound calls work perfectly then. However after a  period of time the gateways are marked as unavailable, approximately 3 minutes.

    If I run a packet capture on the Mediation server I can see the "Request: OPTIONS" packet is sent to the SIP gateway. I then see the response "Status: 200 OK" come back to the Lync server. However the gateway is still marked unavailable after 3 attempts. This is displayed within the Lync Server event log under source LS Outbound Routing. Therefore it looks like the "Status:  200 OK" is being ignored by Lync.

    There are some posts on these forums that suggest this is a bug/change in Lync CU Patch 2.

    I am running Lync Mediation Server patch KB2502810.

    The SIP trunk is to a VoIP SBC switch running Genband RSM version 5.2.


    The Request OPTION contains the following:-

    FROM: <sip:wat-lnc-srvr1.vinciplc.net:5060;transport=Tcp;ms-opaque=6baf0fc846253eb6>;epid=EB343A3975;tag=40dd2e4e84

    The Status 200 contains the following :-

    From: <sip:wat-lnc-srvr1.vinciplc.net:5060;ms-opaque=6baf0fc846253eb6;ms-opaque=6baf0fc846253eb6>;tag=40dd2e4e84;epid=EB343A3975

    I want to determine the cause of this problem. I presume this would be done by seeing if Lync thinks the 200 response is malformed? I have tried to run the OCSLogger tool and monitor the MediationServer component however don not see anything logged and nothing detailed enough is in the event log.

    Is there another way to determine what is causing this? Is this really a known fault with this patch?

    Many thanks for any assistance provided.



    Wednesday, October 5, 2011 9:45 AM


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