Conference call with external telephone number fails RRS feed

  • Question

  • Dear All,


    We have OCS 2007 Standard implemented, and just now we connected to the PSTN using a SIP provider (compatible with OCS).  To limit the amount of open ports and facilitate our firewall config, we reduced the number of used ports on the Mediation Server.  We do not FrontEnd servers.  We can call to external phone numbers without any issue.


    Although we can set up conference calls between users within the company, it seems to be impossible to invite external users (called by telephone number).  We get an error complaining that the user is not found OR that there is no route to the user.  We do have a route, basically saying  all calls to:




    should be forwarded to the mediation server.


    Suppose I invite an external user, I get the message:


     An error occurred during the call. More details (ID:404)


    The more details then show:


    The possible causes for this error message are as follows:

    • There are no routing rules on the Office Communications Server for the phone number you are attempting to call.
    • The contact’s address is invalid.

    Is it even possible to have a three-way call with external users?  Is this caused by not having a FrontEnd server, or a wrong configuration?


    Thanks for your help,


    Best Regards





    Friday, January 25, 2008 11:15 AM

All replies

  • Hello everybody,


    Small update on this issue:


    We now have an AudioCodes MP114 FXO/FXS router in our network.  We can call external lines, and we can call to the FXS ports on the gateway.   A conference call between the FXS port and 2 communicator users works flawlessly.  When we want to conference with an external line using the FXO port, the conference call fails...


    Any suggestion is welcome...



    Best Regards


    Thursday, February 7, 2008 1:43 PM
  • Yep - I'm having the exact same issue....anyone?

    Friday, February 8, 2008 7:24 AM
  • Hi.


    We have the same problem.

    We have a Cisco GW for external calls. We can call 1 extranal client, but not set på conferences with 3 or more extranal phone nr.


    RouteHelper does not show any issues.


    1. Is there any issues or known issues/patches that must be installed solving this ?




    Monday, October 6, 2008 2:06 PM
  • Monday, October 27, 2008 5:07 PM
  • Dear all,


    To be honest this thread escaped my attention over the last few months.  We are now using a net gateway and are not experiencing the issue anymore.  The config of the mediation server and OCS Std server remained the same between the setup with the AudioCodes and net gateway. 


    One thing we did change is that the mediation server now uses only 1 NIC for both incoming and outgoing traffic.


    We do not experience these issues anymore, so it could be gateway related... but it remains a mystery to me.


    Thanks for all your input,


    Best Regards




    Tuesday, October 28, 2008 8:57 AM
  • Sounds familiar;

    Multiple interfaces on the Mediation server could definitely have been the problems (see item #3):




    Tuesday, October 28, 2008 6:00 PM