OCS interworking with SIP server RRS feed

  • Question

  • Hi All,

    I'm working on OCS interworking with my SIP server, but stuck in how to configure OCS. Do I have to use TLS to establish the communication between OCS and my SIP server? I have tried to use TCP, but failed to make call.

    My SIP server is not only a registrar server, but also a SIP proxy. SIP phone can register to my SIP server. What I want to do is to make call between the SIP endpoint registered to my SIP server and Communicator registered to OCS. I have tried to use TCP to establish the communication between my SIP server and OCS. My SIP server is listening on, OCS is listening on The responsible domain of my SIP server is micromethod.com, while that of OCS is ocs.micromethod. I create a static IP route on OCS, the domain of the matching URI is micromethod.com, next-hop is with TCP transport. And I also add into the Host Authorization list and check the box "Treat as authenticated".

    If the call is started from Communicator, the callee SIP phone replies with "415 Unanswered Call Security Mismatch". The SIP phone I use is Bria, I think this error response might be due to the incompatibility of Communicator and Bria.

    If the call is initiated from Bria, when the INVITE message arrived at OCS, OCS responsed with "SIP/2.0 504 Server time-out". But if I uncheck the box "Treat as authenticated", OCS responsed with "SIP/2.0 401 Unauthorized". If I remove from the Host Authorization list, OCS responsed with "SIP/2.0 400 Missing correct Via header".

    Did anyone meet with the problem I describe? Thanks in advance!
    Tuesday, January 6, 2009 2:29 PM

All replies

  • Hi Voxeo,

    Typically the setup you described uses a mediation server to go between different envionments but I do understadn what you are trying to acheive. Tandberg have a similar way of doing things in their VCS configuration. I think the problem you are running into is around the security setting on the client that specifies only secured connections unless your SIP register can do a compatible form or TLS.

    This link may help. It talks about how to do a similar setup your describing but with Tandberg.


    To get this setup to work without TLS you will need to change the security setting . Change from security required to supported should do the trick or you can do it on client through the registry.

    This blog talks mkore about it


    Monday, March 9, 2009 7:55 PM

  • It seems that you are mixing functionality of both Enterprise Voice and Remote Call Control.  Remote Call Control allows you to use the OC Client to control a SIP Registered device (i.e. softphone) that has been registered with an IP/PBX (Softswitch).  In this scenario the OC Client is used for "controlling" the call state only and does not receive/send media.

    To achieve this configuration (RCC) you need to configure the Routes on the Front-End server, the SIP URI on the User object and the Host Authorization List (Treat as authenticated) for the Next Hop.

    For Enterprise Voice, which allows you to receive/send media from the OC Client (i.e. using OC Client as a softphone), you require a Mediation server.  The Mediation Server will require configuration of the next hop (TCP or TLS) and Routing (through Location Profiles etc) but does not require the Front-end Route and Host Authorization config. on the Front-End servers (as this is specific to RCC).

    Wednesday, May 20, 2009 2:28 PM