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Long Delay in Voicemail Greeting RRS feed

  • Question

  • We are wanting to migrate from Exchange 2010 to 2013 but have run into a show stopper. Our PBX is the Mitel 3300 platform which, unfortunately, is not listed as a Direct SIP Partner with Exchange 2013. Our 2010 integration works flawlessly and we use it for voicemail and auto attendants and the Mitel 3300 platform is listed as a Direct SIP Partner for Exchange 2010.

    In test we find than when the diversion of a call with the "reason=no-answer" occurs, there is 10-15 second delay in UM finally responding to the rtp stream generated by a phone. There appears to be essentially no delay when diverting an auto attendant pilot number to the OVA number or when someone is "off hook" and the call is diverted to UM for the "reason=user-busy".

    Does anyone have any experience in integration Mitel with Exchange 2013 or have any ideas as to we might do to resolve the issue?

    Monday, April 14, 2014 7:34 PM

All replies

  • Answered my own question. Ensure that "Enable Mitel Proprietary SDP" is set to no in the Mitel SIP Peer Profile.
    Monday, April 14, 2014 7:50 PM
  • Wow, this is great information!  You may have just saved me a lot of time as I have a few Mitel 3300/Exchange UM clients out there looking to upgrade.

    Please remember, if you see a post that helped you please click "Vote As Helpful" and if it answered your question please click "Mark As Answer". SWC Unified Communications

    Monday, April 14, 2014 8:38 PM
  • Just know that is not the only issue. Earlier testing in the fall showed up another issue which I was hoping to test to see if it is resolved in SP1 but had a major headache with the "No Answer" delay that I did not previously realize as I must have done all my testing by pulling the phone "off hook" to test voicemail rollover (being impatient and all).

    The other major issue is with SIP REFER. With a DAG situation what happened (and probably still does but will know more after I get the test environment back up to EX SP1 DAG) is when a call would come into the OVA number from a phone outside the organization and you wanted to access a mailbox, you would end up in an endless loop if the mailbox was not running in a database running on the answering server. Exchange sends back a SIP REFER telling Mitel to call the OVA at the other Exchange box. Mitel then evaluates that message and says.. "Oh you want me to call OVA ####, let's see, that is in ARS Digits Dialed on Route X, and then sends the call right back down the original trunk.

    I tried everything I could think of and then got Level 3 Mitel support on the line who then told me that they don't currently support that type of SIP REFER. Seriously? Fully SIP supporting eh?

    Anyway, plan to test that all out again with EX 13 SP1 running on 2012 R2. Probably will get same result but can live it. I mean really, how many people really need to call into voicemail from outside? Use a smartphone or OWA.

    Monday, April 14, 2014 8:53 PM
  • I have the "enable mitel proprietary sdp" set to no, and I still receive the delay. would you be able to share the other settings you have setup in the Mitel?
    Thursday, October 29, 2015 1:54 PM