Dual Call Forking - CUCM 7.0.2 RRS feed

  • Question

  • Hi All,

    We currently run CUCM v7.02. We've integrated it with our OCS 2007 R2 Enterprise environment by Direct SIP using mediation servers.


    So far everything has worked as expected, until we tried integrating users on Cisco hard phones with entrepise voice enabled MOCs running on their PCS. The requirement is to run the two endpoints with the same phone extension number; hence the need for dual forking.

    I've come across with a cisco doco with a workaround for forking on call manager. I understand that is based on the Unified Mobility feature of Cisco, which is working for us partially. I also understand that for simplicity is recommended to use two different numbers one for the cisco directory number and the remote destination number in this case the moc extension number. But this does not suite our requirement.

    So at the moment we have the cisco and the moc ringing simultaneously whenever the calls are originated internally from any cisco phone or externally when dialing the DID. The problem we experience though is when dialing internally from any of the moc clients, in this case instead of the two phones ringing simultaneously, only the MOC rings. This is so since OCS recognizes the extension as a local number; normalising it and then routing it internally making only the MOC client to ring.

    I wonder if anyone has come across with a similar issue. I will appreciate some feedback on this and any approaches to work around it.



    Friday, March 27, 2009 5:09 AM

All replies

  • Well im having the same setup and problem, so i hope we can solve it and share how we did
    BTW is this the doc u are refering to?? http://www.cisco.com/en/US/docs/voice_ip_comm/cups/7_0/english/integration_notes/IntegrationNoteOCS_CUP70_MOCCallControl.html


    Friday, March 27, 2009 11:13 AM
  • Hi VoIPAdmin and Tommy,

    The behaviour you desicribe is really expected as this isnt true dual call forking. With the Cisco Sim ring feature all the call control over your DID for ringing the Cisco phone will only happen if the call orginates from with the Cisco enviroment and not OCS. When you call from OCS you are ringing a MOC internal number and unless you work out a way to force that call out of OCS to the Cisco enviroment the Cisco IP phone will never ring because like I said its not true dual call forking. Sorry for the bad news but until Cisco supports dual call forking your stuck with what you have.


    Friday, March 27, 2009 3:17 PM
  • Just a comment.
    This is by design and  it's the same on Nortel CS1000, but here you have the option to use Dual forking and Remote Call control together, and then the desk phone will ring.
    You could do a work around and use the "Simultan ring" in Communicator to make your deskphone ring, but then you need 2 numbers, one for deskphone and one for Communicator.
    You won't have the presence information (in a call) on the deskphone when you only have dualforking, this will only be supported  when using DF and RCC together, but this isn't supported on Cisco as far as I know.

    I never recommend dualforking as "standalone" and who need a deskphone when you have Communicator ;)

    Jan Petersen
    Sunday, March 29, 2009 10:07 PM
  • Hi Tommy,

    This is the doco i was referring to, http://www.cisco.com/en/US/solutions/collateral/ns340/ns414/ns728/ns784/716742.pdf. Have you seen it?

    I'm not using Cisco Unified Presence. Instead i'm using the microsoft mediation servers for the integration with call manager by means of SIP trunks.


    VoIP Admin
    Sunday, March 29, 2009 11:39 PM
  • Regardless of the phone system on the other end of the Direct SIP connection, what the OP is describing is NOT expected behavior from OCS's standpoint.  If an OCS user is proper configured for Dual Forking then OCS will ring BOTH the MOC and PBX endpoints.  Make sure that you have the user set for Enable Enterprise Voice and Enable PBX Integration.  Only the Line URI field need populating in this case as the Server URI is left blank (it's used only for RCC).

    Take a look at this excellent blog article which explain the different telphony use cases in OCS:

    If OCS is configured properly then take a look at the SIP traffic leaving the mediation server to verify that the call is sent oubound.  If so, then your gateway/PBX may be suppressing the ring internally.

    Jeff Schertz, PointBridge | MVP | MCITP: Enterprise Messaging | MCTS: OCS
    Monday, March 30, 2009 11:58 AM
  • Hi Jeff,

    If Voipadmin were to use what you are suggesting in combination with the Cisco document it could cuase some serious issues. CUCM is not designed to do dual call forking so you would end up with calls bouncing backwards and forwards multiple times. In the Cisco document it makes it clear through a screen shot not to enable Enable PBX Integration. Just wanted people to relise if you use the mobility function in the Cisco enviroment and enable SIM ring from the Cisco point of view then you cant do dual call forking from the OCS standpoint. If on the other hand you only did the OCS forking and had inbound DID come directly into your OCS enviroment rather than via CUCM then that would work.

    Monday, March 30, 2009 4:04 PM
  • Chris,

    You are correct, I should have clarified my response a bit more.  I was responding the Tommy's original statement that this behaivor is expected due to OCS only routing the call internally.  It's not OCS that is failing to send the dual forked call, but the way the attached phone system that handling the call, which you've pointed out.  Thanks for catching that.
    Jeff Schertz, PointBridge | MVP | MCITP: Enterprise Messaging | MCTS: OCS
    Monday, March 30, 2009 4:58 PM