Polling algorithm for sip trunk RRS feed

  • Question

  • Hi there,


     I’ve urgent need to understand in deep dive the following topics about MSFT Lync:


    Polling algorithm for sip trunk

    ·         how a sip trunk is defined up or down by mediation, which is the algorithm (reading post it seems using SIP OPTIONS request looks like keepalives)?

    ·         What is the correct response to the SIP OPTIONS request to declare a trunk up?

    ·         What is the balancing algorithm used in the case of routing more calls to more sip trunks configured with a pool of mediation (round robin, ...)?


    many thanks in advance

    carlo serasso
    Thursday, January 5, 2012 1:23 PM


  • Hey Carlo,

    For an excellent explanation on how the SIP trunk is defined as up or down, see Jason Shave's blog post here:  http://jasonshave.blogspot.com/2011/12/lync-server-2010-building-redundancy.html

    In terms of balancing calls between multiple mediation servers, on the Lync side of things, if you have multiple mediation servers defined for a route, outbound calls will round-robin between the two (unless one is down, of course).  

    If you want to set things up in terms of primary/secondary, then you would need to create separate routes and apply those routes to separate usages.  Put the usage you want used most often higher up in the voice policy than the secondary, and calls will always go to the primary first, unless its down.  See this post on my blog for more info: http://ucken.blogspot.com/2011/01/enterprise-voice-best-practices-in-lync_21.html



    • Proposed as answer by KenLaskoMVP Monday, January 9, 2012 2:18 PM
    • Marked as answer by serasso Monday, January 9, 2012 2:37 PM
    Thursday, January 5, 2012 8:33 PM