Skype for Business Dial-in Conferencing RRS feed

  • Question

  • We have Lync Server 2013 and Skype for Business Server in Co-existence.Lync Server 2013 is installed on Site 1 and Skype for Business Server 2015 on another Site 2.

    At present Lync 2013 is integrated with EPBX for Dial in funtionalilty so PSTN Gateway and Trunk are defined under Site 1 only.All Dial plan and normalization rules are defined as GLOBAL Scope.

    I would like to know,  do we need to add another gateway for site 2/Pool 2 ? if not How can we migrate Dial-in number after migrating all users from Lync 2013 ?

    At present, SFB user is also getting dial-in information when they schedule any SKype Meeting but Conference ID always comes with five digit although when Lync 2013 user schedule, they get six digit conference id. Not sure why this difference is ?

    Please suggest.


    Wednesday, June 15, 2016 7:57 PM

All replies

  • Any suggestion please ?
    Thursday, June 16, 2016 8:04 AM

    Once all users are migrated , Dial in conference should be migrated as they are Application End points.

    When you remove the Lync 2013 Server and if you are removing the site as well , then you should consider moving the GW to the new site.

    I think its ok for havig 5 digits or 6 digits as the logic it uses in building the Con ID is with calculating the Conf Directories and other things , which in our case is new as SFB is just installed and when it has more conference directories in picture it should start sending 6 digits. 

    Reference (2013) - Still valid for SFB 




    • Proposed as answer by Eason Huang Thursday, June 16, 2016 10:56 AM
    Thursday, June 16, 2016 9:59 AM
  • you need to create sip trunk using SFB meditation with your EPBX

    then change in routes in voice policy that use lync sip trunk to use the new SFB one

    then from EPBX transfer the calls to SFB instead of Lync

    then you could decommission the lync 

    • Proposed as answer by Eason Huang Thursday, June 16, 2016 10:56 AM
    Thursday, June 16, 2016 10:11 AM
  • Hi JinDeep,

    Base on my understanding, it is supported scenario to configure pool 2 to collocate the Mediation Server of Pool 2 with the same gateway used by pool 1.

    If you assign a voice policy for the user of the other pool with the trunk, the users can use gateway of pool 1 for PSTN calls.

    Creating multiple conference directories will ensure that conference IDs will stay short until a significant amount of conferences have been created. In an organization with a typical number of conferences per user, we recommend that you create one conference directory for every 999 users in the pool. Using this guideline the conference IDs can generally be kept small. However, once the number of conference directories (across the pools) exceed 9, the Conference ID number will grow to support additional conferences.

    For details, please refer to


    Here is a similar case for your reference


    Best regards

    Please remember to mark the replies as answers if they help, and unmark the answers if they provide no help. If you have feedback for TechNet Support, contact tnmff@microsoft.com.

    Eason Huang
    TechNet Community Support

    • Proposed as answer by Liinus Thursday, June 16, 2016 11:11 AM
    Thursday, June 16, 2016 10:55 AM
  • Hi,

    Can we have 2 PSTN gateway ? One is configured in Site 1 and second configured in site 2 and both share same Dial in conferencing number ?

    Actually we do not want to interrupt current Dial-in configuration.Is there any way through which we can add secondary PSTN gateway using same dial in number so that once all user gets migrated to SFB pool , we just need to migrate dian-in access number to SFB Pool and remove  primary PSTN gatway & trunk.

    Also please suggest what are the task needs to be consider while moving Gateway from Site 1 to Site 2.


    Monday, June 20, 2016 2:48 PM
  • Please suggest.


    Tuesday, June 21, 2016 9:53 AM
  • Please suggest what are the steps/risk involved while moving gateway from Pool1 to Pool2.


    Wednesday, June 22, 2016 8:06 AM