OCS Standard setup - SIP trunk RRS feed

  • Question

  •  Hi, we're evaluating OCS (R2) Standard for use in our (30 user) office and have a couple of questions. We are in managed offices and do not have access to the existing PBX, so our intention is to go fully VoIP and use SIP trunking to an ITSP. Can you advise the actual topology required, allowing for external access as well? Is it:

    1. Windows Server 2003/2008 with OCS Standard (Front-end Server)
    2. Windows Server 2003/2008 with OCS Standard (Mediation Server)
    3. Windows Server 2003/2008 with OCS Standard (Edge Server)

    So, three physical servers, three Windows Server licences, three OCS Standard licences? Can these be virtualized?

    Is a mediation server definitely required if using SIP trunking? Or are there alternatives?

    Tuesday, February 17, 2009 2:51 PM

All replies

  • The Mediation is required as it's the OCS component that will establish the SIP trunk and handle Voice codec/protocol conversion.  You can virtualize any of the components, but it's neither supported nor recommended.  In a 30 user office, dependingo n the hardware and concurrent usage you could probably get away with virtualizing the Front-End and Edge server but I've used a virtual Mediation server and VoiP calls can be a terrible experience.  And if heavy audio/video conferencing will be used then I'd further recommened against any virtualization of any of the server components. 
    Jeff Schertz, PointBridge | MVP | MCITP: Enterprise Messaging | MCTS: OCS
    Tuesday, February 17, 2009 5:16 PM
  • Thanks for that, that makes sense. What's confusing is that on a TechNet page: http://technet.microsoft.com/en-us/office/dd441250(office.13).aspx?ppud=4, it states:

    That's nice, but the cool thing is that it does all this without requiring additional hardware like IP-to-PSTN gateways or Mediation Servers. Instead, all you need is an account with a SIP trunking service provider.

    ... and an OCS Mediation Server :)

    Thursday, February 19, 2009 2:14 PM
  • I had a call with Microsoft Technical Sales Assistance on this issue and this is the response:

    For your scenario you will not require Mediation server if ISP is

    1)      Sending SIP traffic on TCP and

    2)      Sending audio using RTAudio


    For your scenario you will require Mediation server if ISP is

    1)      Not sending SIP traffic on TCP and

    2)      Not sending audio using RTAudio

    Configuration is then done on the Edge server, something we'll be investigating shortly...
    Friday, February 20, 2009 12:08 PM
  • This is not right , by all ways you will need Meidation server , Edge only handle the follwoing :
    Access : Communicator External Access
    Web Conf : Live meeting external access
    AV : Audio and video conversations from outside.

    by all ways you will surely need Mediation server ...trust me :-)
    you will find much more information about all kind of integrations on my blog http://theucguy.wordpress.com/ 
    Friday, February 20, 2009 7:32 PM
  • Just to echo what everyone else has said, you will absolutely need a Mediation server.  Futhermore, there are only a small number of ITSPs supported by OCS out of the box.  In March my company is releasing a product that allows you to integrate OCS with any ITSP.  I'll post back to the forums and on my blog when it is released.
    Mike Stacy | Evangelyze Communications | http://www.evangelyze.net/cs/blogs/mike
    Saturday, February 21, 2009 4:07 PM
  • I agree with what everyone is saying here. At a minimum you will need a medaition server, even for the qualified direct SIP trunking SP. Why technical sales would say other wise I am not sure at this isnt an option at the moment.The technet page is also incorrect as far as I know, no service provider is able to do TLS, TCP SIP connections while supporting RT audio codec. Hence why you need the mediation server.

    Chris http://voipnorm.blogspot.com/
    Thursday, February 26, 2009 6:01 PM