connecting Mitel 3300cx and OCS RRS feed

  • Question

  • I am trying to connect an Mitel 3300CX (with SIP trunk option installed) to the OCS but nothing is working.


    My  first doubt is: Even apparently this is one of the PBX that support direct SIP trunk to the OCS, without having to use the Mediation Server, we are not able to put both two systems communicating between them. Does everyone ever install this solution? If yes, can I have any help here configuring the OCS?



    • Moved by Matt Sousa - MSFT Thursday, December 17, 2009 6:58 PM forum migration (From:Telephony)
    Sunday, November 18, 2007 7:42 PM

All replies

  • I think you a bit off base here. You may be able to connect this without a gateway but you will require a mediation server


    Why?  The mediations server transcodes RTAudio to G.711 which standard PBX's understand.


    The advantage to the Mitel is you should not need a device like an Audiocodes or Quintum between the meidation server and PBX


    I know of no PBX that natively understands RTAudio



    Monday, December 3, 2007 11:20 PM
  • The Mitel 3300cx is not qualified to connect directly to OCS 2007. The official list of supported and qualified gateways and IP-PBX is here http://technet.microsoft.com/en-us/office/bb735838.aspx. At this point in time the only available option is to use one of the qualified gateways.


    best regards


    Tuesday, December 4, 2007 7:35 AM
  • I know that Mitel 3300 CX is not qualified to connect directly to the OCS 2007 using a SIP trunk but I ebelive we can do this using a Mediation Server. Correct?

    best regards

    Tuesday, December 4, 2007 5:11 PM
  • No. When I wrote OCS 2007 above I was referring to the full OCS 2007 environment including Mediation Server. Please have a look at this web site http://technet.microsoft.com/en-us/office/bb735838.aspx for the qualified and supported connectivity options. At this point in time you need a media gateway.


    best regards



    Friday, December 7, 2007 9:05 AM
  • Hi there Toni_2007,


    To clarify Mitel's integration with Microsoft - there are 3 different levels to consider:

    * Integration to Exchange 2007 to support MS speech AA, Outlook VM/UM etc...

    * Integration to MS OCS for presence / collaboration to provide telephony capabilities etc...

    * Using the OCS client as a SIP softphone device


    Mitel is one of 3 <?> vendors to release a direct SIP Trunking integration to Exchange 2007 (as per Microsoft's website). No audiocodes or other 'mediation server' required.


    Mitel is also part of the Microsoft Partner Ecosystem for OCS integration - but to integrate, suppoprt and EXTEND the funcationality of the Microsoft OCS product, we introduce the Mitel Live Business Gateway which essentially translates the Microsoft protocols into the Mitel protocols so we can enable the OCS client with click to call, 8-party conferencing, and ability to twin your cell phone to your desk extension and still maintain "in a call" presence status.  Beyond that we also leverage the Microsoft OCS presence engine to push presence information into most of our applications (such as contact centers for first contact resolution) and directly to our large-display sets.


    To use the OCS client as a SIP Softphone, the Mitel simply sees the client as a Generic SIP device. (which is a device license per client).


    See this page for more information http://www.mitel.com/DocController?documentId=25323


    Hope that helps.


    Tuesday, February 19, 2008 10:30 PM

  • Hi Kmowat

    After some "fight" with Mitel 3300CX and the OCS we have now everything in place and working perfectly. Meaning:

    - we have the Mitel 3300Cx with a direct SIP trunk to the Exchange Server 2007,
    - we have the Mitel 3300CX (without the Live Communication Server) "talking" to the OCS (throught the Mediation Server)

    with the above in place we are now able to:

    - from outside access our Exchange "Voice" mail box,
    - to speak between any IP Phone to any Office Communicator client,

    Anyway thanks for your post

    best regards


    Thursday, February 21, 2008 12:38 AM
  • Antonio (or anyone),


    When you say you have it all working, what exactly have you done and what exactly have you got?


    1 - Is OCS in Enterprise Voice mode with Full PBX Integration, or is it just Remote Call Control (RCC)?

    2 - Did you need the Live Business Gateway to sit in between the Mediation Server and the Mitel 3300?

    3 - Are you able to call from Office Communicator to a Mitel IP Handset, and vice versa?


    This would greatly help me!





    Wednesday, February 27, 2008 5:48 PM
  • Hi Steven,

    I don't have much time today but just to give you some quick answer to your question:

    1 - OCS is in Voice Mode
    2 - No. We have the MITEL 3300 CX conecting directly to the Mediation Server using a SIP Trunk (we are not using the Mitel Live Business Gateway)
    3 - Yes. Internally we have this fully working. The only thing that it is not working is if we have someone out of the office phoning to the company using the communicator the IP Handset rings but as soon someone answer the call we have a white noice. We believe this must be a port problem in the firewall but it is not really urgent to us we did not yet lose time with this.

    best regards
    Wednesday, February 27, 2008 6:24 PM
  • Steve, the following (if I'm allow to add on this...)


    1) Mitel can do RCC with the LBG and Enterprise voice through the SIP trunk into mediation server

    LBG will not go away as you will need it for RCC to Mitel phones


    2) LBG does not having anything to do with mediation server. LBG is a "signalling" gateway between the OCS pool and Mitel. So if you want RCC you need LBG, if you only want pc-to-phone and vice versa you need the SIP trunk to mediation


    3) If you use the SIP trunk (formally supported in 8.0 UR3) than you will be able to dial from OC "softphone" to Mitel ands outside lines and vice versa


    Also mentioned in one of the earlier replies, you can't just add a SIP device to the OCS server......as Microsoft is not using the standards here. You can only use the Microsoft approved OCS endpoints, so a general SIP phone will not work.


    Hope this adds, if not let me know.




    Wednesday, February 27, 2008 6:34 PM
  • Thanks guys, for the info. I need to dig a bit deeper.


    So there seems to be a bit of conflicting info here then. RCC is required to make the Mitel phone do the calling, which I will require for users that don't have a UC endpoint (Tanjay etc). So users with a laptop on their desk and a Mitel phone can simply call from their phone. But also required is the ability for users with a UC endpoint on their desk (and laptop) to make calls from their endpoint or Communicator to other endpoints AND Mitel desk phones AND to external PSTN numbers. So it's basically the full PBX integration that's required. Is this something the Mitel can support? Some say it's just RCC and you need LBG, other say its PBX integration and you dont need LBG! Confusing!


    I know that there are various modes to work in (RCC only, PBX Integration etc) all defined in the group policy template for Office Communicator, so I need to know which one to enable here too.


    We don't yet have 8.0 UR3 (we lost that support since Mitel pulled the plug on UK distributors) or LBG so we need to know exactly what is required. Then maybe we can find the software somewhere!


    Appreciate the help on this everyone...



    Thursday, February 28, 2008 11:07 AM
  •  Toni_2007 wrote:
    Hi Steven,

    I don't have much time today but just to give you some quick answer to your question:

    1 - OCS is in Voice Mode
    2 - No. We have the MITEL 3300 CX conecting directly to the Mediation Server using a SIP Trunk (we are not using the Mitel Live Business Gateway)
    3 - Yes. Internally we have this fully working. The only thing that it is not working is if we have someone out of the office phoning to the company using the communicator the IP Handset rings but as soon someone answer the call we have a white noice. We believe this must be a port problem in the firewall but it is not really urgent to us we did not yet lose time with this.

    best regards


    Do you have any docs or instuctions on how you got this working?



    Thursday, May 1, 2008 7:32 PM
  • Just to add on this, we have a fully working system with the Mitel 3300 in all regards. External users can make calls properly too. We did have the help of Mitel themselves too.





    Friday, May 2, 2008 8:08 AM
  • Hi Steve,

    Could you possibly describe your setup please as I'm having trouble getting my head around the required topology for Mitel/OCS/Exchange.

    We've just installed a Mitel 3300 (8.0 U1) with an LBG and want to connect OCS 2007 and Exchange so that internal and external callers can leave voicemails and also access OVA.  Do I need to have a mediation server between the Mitel 3300 and OCS?  At the moment we've got a SIP trunk directly to Exchange to allow voicemail but this prevents us allowing users access to OCS.

    If you've got a rough guide to how you're set up I'd really appreciate it.

    Many thanks.

    Wednesday, May 7, 2008 11:27 AM
  • Hi Chris,


    Sure. We've got an OCS Std, a Mediation, an Edge (all 3 roles), a DC/Exchange07 (all roles inc UM), and a Mitel 3300. We're running UR3 on the 3300 too, which I advise you get so that you have the full OCS functionality. The next releases will also look to include proper call forking from the Mitel side which is the last piece in the jigsaw.


    We don't use a LBG because we don't use RCC from OC to the Mitel phones. We just use Enterprise Voice. We have a SIP trunk between the OCS Mediation Server and the Mitel 3300 and that's it. The Mitel is set to route all dialled calls beginning with a 7 to OCS Mediation Server via the SIP trunk. Nothing out of the ordinary there. OCS is just set up in the usual manner and talks happily to Exchange, so we don't have a separate SIP trunk from the Mitel to Exchange. We could do if we wanted though.


    To have external callers leave voicemails directly onto OCS extensions, you'd need DDI's assigned for each one routed through the Mitel. Alternatively just access to the OVA Auto Attendant which could then route callers through to the correct user extension. Both methods would require rules in the Mitel 3300 that directs the call to an extension that corresponds to the one assigned to the Auto Attendant.


    You don't have to use TLS from the Mitel 3300 to the Mediation Server, just use TCP.


    MITEL <-----> Mediation <-----> OCS Std <-----> Users




    Exchange <-----> Users


    OCS Users can call out from their Communicator clients, and also from Communicator Phones. Users can have both Mitel and OCS phones on their desks as they are all assigned different extensions. E.g. I can call my Mitel phone on extension +314 from Communicator, and I can also call my Communicator extension +714 from my Mitel phone. All can call externally too. I can also call the Exchange Auto Attendant on +750 and gain access to the directory etc. Voicemail is easy to retrieve from Communicator too, and conversations are saved in Outlook.


    Not sure where you're going wrong really, the main issue for us was setting up the Mitel properly as I'm not a true Mitel engineer!

    Wednesday, May 7, 2008 12:21 PM
  • Hi Steve,

    Thanks for the speedy reply.  It's interesting that you've given each user separate extensions for their communicator and mitel phones.  Are both numbers set up in AD?  If so, are the mitel numbers just added as additional EUM addresses?

    From what you describe it looks like I need to sort out a mediation server to sit between the Mitel and OCS boxes.  I think we were hoping that the Mitel LBG would do that but perhaps that is not the case.

    I take it that if an internal user calls another internal user then they are able to leave voicemail?

    Many thanks.

    Wednesday, May 7, 2008 1:06 PM
  • Hi Chris,


    If you assigned users with one extension number for both Mitel and Communicator phones, you'd end up with them endlessly ringing simultaneously. It's better to assign two extensions and use the simultaneous ringing feature in Communicator. The Mitel call forking isn't quite ready yet I understand.


    I have +714 and +314. The former is my Communicator extension and the latter is my Mitel extension. If someone calls +714 I can set Communicator to also ring my Mitel extension. If someone calls +314 it will only ring my Mitel.


    I only have one extension number set as an EUM address, that being +714. You can take the Mitel extensions out of the equation almost. I have +314 set up as my 'Telephone Number' in AD and also as an additional 'Work Number' in Communicator Phone Settings. That way, if someone wants to call me on my Mitel (which can only ever be my work phone since I can't take it ouf of office), they can click the call button and hit 'Work' instead of communicator call.


    If anyone calls a Communicator extension, voicemails can be left no problem.


    You need to do what we did, and that was to decide if we really want to do Remote Call Control. We decided against it in the end, and thus decided we didn't need an LBG server. I don't think the LBG can do the mediation but I could be wrong. If all you are doing is RCC then you don't need mediation, since everyone calling externally will be doing it via their Mitel phones already on the external PSTN/ISDN network.


    Wednesday, May 7, 2008 1:35 PM
  • Hi Steve,

    I see what you mean.  I think that we're pretty dead set on RCC unfortunately.  How do you configure Communicator to do the simultaneous ringing?

    So in order to get the Mitel phone to ring at the same time as Communicator there needs to be a mediation server - correct?

    I know this is really cheeky but are you in the UK by any chance?  Our Comms supplier hasn't been brilliant with the implementation and I could really do with a look at someone elses setup.

    Many thanks again.

    Wednesday, May 7, 2008 2:23 PM
  • It's just an option in Communicator. Set it to simultaneously ring another number and enter the number of the Mitel extension.


    Yeah you need a Mediation Server to translate from G711 or G729 into RTAudio, so for the simul ringing to reach the Mitel you need to mediate.


    I am in the UK yes, I can answer your brief questions if you need to. We're a systems integrator and Unified Comms specialist in Merseyside. If you want to discuss further off here feel free. I'll need an email?



    Wednesday, May 7, 2008 2:47 PM
  • That sounds excellent - many thanks indeed.  My e-mail is chris.delaney@malvernhills.gov.uk.


    Wednesday, May 7, 2008 3:20 PM
  • Hi Chris,

    Sorry for this delay answering your question but even so here goes

    What we have in place is a Edge server (in a DMZ), an OCS (he mediation server is a part of the OCS), an Exchange Server 2007 and a Mitel 3300 with two SIP Trunks.

    What are we doing so far? Everyone has a notebook with a Comunicator installed and all their voice call (being internal or external) are answer and done by the comunicator. Also we have some IP Phone which also receive and are able to call externally to of the Comunicators.

    Our pool of phone numbers works like this: IP Phone starts by 9, comunicators start by 7 and 5000 is the number to reach the Exchange Mail Voice.

    The only things we were having problem was in having someone out of the office using their comunicator to phone to someone in the office and vice-versa. According to Microsoft the problem is in the fact that we have the Edge server (our AD server) in the DMZ (and therefore out of the LAN) which is the reason for this situation. Anyway as this is not a problem we did not yet spend more time to solve it.

    If you want we can try to send you some print screen with the configuration we have either in the OCS as in the Mitel 3300 to see if this can help you. If you believe this can be usefull to you just send me an email so I can send the print screen.

    Best regards
    Wednesday, May 7, 2008 11:58 PM

    The only things we were having problem was in having someone out of the office using their comunicator to phone to someone in the office and vice-versa. According to Microsoft the problem is in the fact that we have the Edge server (our AD server) in the DMZ (and therefore out of the LAN) which is the reason for this situation. Anyway as this is not a problem we did not yet spend more time to solve it.


    I assume you mean the AV server is the edge, not AD. For the record you should never have AD installed on a machine in the DMZ. The problem from my experience with calling from external connections is a matter of poor certificate security and/or not using the setup wizard to configure services once too many changes have been made. Be sure to go back and run the config on the OCS server again, even if verification comes back with no errors
    Thursday, May 8, 2008 6:53 AM
  • Hi Toni,


    Many thanks for your setup details.  My e-mail address is: chris.delaney@malvernhills.gov.uk so if you could send some screen grabs that would be really useful.


    I've discovered that if I enable users for Enterprise voice with PBX integration all the voicemail functionality disappears from Communicator - do you know if this is correct?




    Thursday, May 8, 2008 9:59 AM
  • Hi everybody,

    We are in canada and we are planning to deploy an OCS solution to work with our Mitel 3300.

    We are trying to understand exactly what should be our topology.

    I will explain the needs, and if someone can help us understand what will be required it would be greatly appreciated.


     - We want have an intelligent IVR that will dsipach calls to the rights reps by identifing the customer, and verifying some information stored in our BD. 

     - We will have to manage Wait Queues, so cutomer can wait for agents in a group or wait for a specific agent ( queue by group and queue by agent). We need to be able to "re-Sort" the queues based on customers plans.

     - we need to be able to record voice message and store information of the records in our Database.

     - Some of our agents will use Communicator soft phones, some will use our IP phones

     - we want to record conversations and store them as Mp3 files.

     - we need to be able to dial out from soft phone or IP phone

     - we need to be able to dial Ip phone from soft phone  and vice versa





    Wednesday, June 25, 2008 1:08 PM
  • Hi guys,

    Do the MITEL 3300 LX & ME consoles qualify?

    I'm trying to connect a 3300 MX to OVA  MITEL

    Tuesday, February 17, 2009 11:20 AM
  • Hi Sébastien,

    I am a telecom consultant involved in similar projects and I am wondering if you have successfully completed your installation.  I may have new items and resolutions to provide as I work closely with Mitel on this type of projects.

    Please let me know what sort of environment and topology you have in place; OCS R2 have evolved in a more fluid solution since your last post, and release 9 for the 3300 seems to have simplified the interaction between platforms.

    Merci !

    Monday, March 9, 2009 4:17 PM
  • Pierre,

    In your reply, you had mentioned OCS R2.  Did you have any luck with OCS 2007 R2? 


    Monday, June 8, 2009 4:35 PM
  • I too would be interested to know if there is any specific requirements to connect a 3300 to OCS 2007 R2 that were not required with 2007 RTM.

    We have OCS 2007 R2 Enterprise front end, edge, cwa and mediation on the OCS side, with LBG and Mobile Extension and a 3300 on the Mitel side. I'm currently trying to get this working together, but I can only reliably set users up for RCC. The Enterprise Voice + Dual Forking scenario fails to connect voice calls between the two systems through the Mediation server, yet both Mitel IP Phones and OCS endpoints ring correctly.

    Anyone else currently working on this, or have it setup already?

    Wednesday, November 4, 2009 10:39 PM
  • Please refer to http://technet.microsoft.com/en-us/office/bb735838.aspx#direct
    You will see that Mitel has not yet qualified the 3300 against the OCS R2 OIP requirements.
    Therefore at this point, this is not a Microsoft supported setup.
    I would encourage you to inquire with Mitel.
    Sunday, November 15, 2009 1:04 AM
  • Mitel appear to have this working according to some of their website docs. I'm okay with it not being on the support list yet (and have asked Mitel to consider submitting for testing) but would like to get my pilot working anyway. Has anyone got a 3300 connecting and relaying voice with an OCS 2007 R2 Mediation server?

    Wednesday, December 2, 2009 9:14 PM
  • I had written some docs on setting this up, I decided to create a blog on it and start posting the docs i've written. Let me know if you have any questions.



    Friday, December 4, 2009 6:24 PM
  • Hi All,

    I was just reading through this thread since we're going to attempt to set up Mitel / OCS R2 integration in the next couple weeks.

    According to Mitel (http://www.mitel.com/DocController?documentId=28140):

    "Mitel has successfully completed Microsoft® certification testing for direct SIP connectivity between Mitel 3300 IP Communications Platform (ICP) and Office Communications Server (OCS) 2007 R2. Mitel is now listed on the Microsoft web site as a certified PBX vendor for direct SIP connection.
    http://technet.microsoft.com/en-gb/office/bb735838.aspx#ippbx1. "

    The weird thing is that the Microsoft site referenced doesn't have a checkbox in the R2 column (though they clearly state R2 in the link above).

    Tuesday, December 8, 2009 9:57 PM
  • Hi Rob, I came across the same article regarding 2007 R2 being supported and brought this omission up with our Mitel contacts.

    We now have our 3300 connecting to OCS 2007 R2 with Mitel Mobile Extension and Mitel Live Business Gateway taking care of Dual Forking to the Mitel IP Handsets and Remote Call Control respectively. This, so far, seems to allow every possible scenario depending on what a user needs. Still a lot more testing to do though.

    There are a couple of niggles we are working through with 3rd line support but the excellent Mitel engineer has it all setup the same in his test lab and is very knowledgeable of both the Mitel and OCS side, which has helped enormously to get it working.

    I also have a couple of issues with Edge (Mediation server suddenly wants to connect to the edge the external interface!! - i dont think i "get" the a/v auth thing yet) and Dial Plans but I think these are down to me needing a bit more research.

    Thursday, December 10, 2009 8:13 PM
  • Hi M,

    Thanks - it's reassuring to find that it will indeed work.

    We're in the process of setting it up now.    We are having some trouble establishing the basic sip trunk from the 3300 to the mediation server.    It seems like it should be pretty basic, but the mitel always shows the link as "Out of Service".   If I force it to always on, I can see the sip messages coming in to the mediation (using a packet sniffer), but it never seems to reply to them.  

    The mediation server setup options seem to be pretty basic, so I'm thinking it must be either something on the Mitel side, or some sort of network issue.   I've compared our settings to the list posted by Habib above (thanks for the comprehensive list, btw Habib - that type of info seems to be very rare for some reason).

    Out of curiosity, did you run into any snags when attempting to set up the sip trunk itself?  I understand the dial plans / routing are a whole other issue. 


    Friday, December 18, 2009 4:29 AM
  • For anyone. I have a little quirk. We have installed and migrate to Microsoft UC. We have RCC users as well as EV users. We have a Mitel IP 3300 running Ver 10 MSD 4.0. Before we upgraded to Mitel ver. 10 all call flows worked with no problems RCC to EV, EV to RCC, RCC to EV Voicemail, and EV to RCC voicemail. Now after the upgrade to Mitel ver 10 and also MS Exchange was upgraded to Service pack 2.  When a EV user(extension) calls a RCC user(extension) and the call is not answered. The call is connected to Exchange VM and this is were we are having the problem. The exchange VM hears nothing from the EV user and repeats asking are you there. IF a RCC user(extension) calls a EV user(extension) there is no problems. Now to throw another twist in the mix. When a EV user calls the RCC  10 digit phone number there is no problem. It happens only when it is a station to station call.
    Friday, April 23, 2010 8:57 PM
  • Tony52 - just curious if you found a solution to your problem.   We've run into exactly the same issue.




    Tuesday, June 1, 2010 7:24 PM