Exchange Unified Messaging and Trixbox 2.8 Howto

Now that Trixbox has incorporated Asterisk 1.6, as of Trixbox 2.8 Beta, configuring it to access Exchange Unified Messaging is pretty simple.  This will be a quick and dirty howto in which I will assume that the reader is somewhat familiar with both Exchange 2007 and Trixbox.

Once you have Trixbox installed and working with one or more extensions, you will need to configure SIP to allow TCP connections by editing /etc/asterisk/sip_general_custom.conf and adding the following lines:


This will enable SIP over TCP and bind the protocol to all network adaptors in the system.

Your next step is to configure a SIP trunk from the PBXConfig section of the Trixbox Web Administration Tools.  It should be created as follows:

Outgoing Settings:

Trunk Name: Exchange

PEER Details:
host=[IP Address of Exchange 2007 UM Server]

Save this trunk and add a new outbound route:

Name: Exchange

Intra Company Route: Checked

Dial Patterns:

Trunk Sequence:

Save the route and apply the changes.

Now we need to configure Exchange:

In the Exchange Management Console under Organization Configuration -> Unified Messaging:

New UM Dial Plan:
Name: Asterisk
Number of digits in extension numbers: I chose 4, but if you use a different number of digits in you extensions, put what makes sense for your configuration.

New UM IP Gateway:
Name: Asterisk
IP Address: IP of your Trixbox Server
Dial Plan: Choose the Asterisk Dial Plan you just created.

New UM Mailbox Policy:
Name: Asterisk
Dial Plan: Choose the Asterisk Dial Plan you just created.

New UM Auto Attendant:
Name: Asterisk AA
Dial Plan: Choose the Asterisk Dial Plan you just created
Extension Numbers:
Create auto attendant as enabled: checked
Create auto attendant as speech-enabled: checked

Now view the properties of the Asterisk Dial Plan and go to the Subscriber Access tab. Add a new telephone number to associate: 8888. Go to the Setting tab and choose G711 for the Audio codec. Press OK.

Now, in the Exchange Management Console, go to Server Configuration -> Unified Messaging. View the properties of your UM server there and click on the UM Settings tab. Add the Asterisk Dial Plan and click OK.

The last step is to go to Recipient Configuration -> Mailbox and enable Unified Messaging on a mailbox there.

Now just dial 8800 from your extension on the Trixbox server and if everything went right you should be connected to Exchange Unified Messaging!

Thanks to the author of this page for the Asterisk configuration example:

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10 Responses to “Exchange Unified Messaging and Trixbox 2.8 Howto”

  1. Savi Thomas September 3, 2009 at 5:38 pm #

    Super simple, I was looking for this, thank you so much.

  2. Alex P October 1, 2009 at 3:56 pm #

    This guide is great.I have tried the setup with trixbox 2.8.1 However everytime I dial extension 8800 i get all circuits are busy.Anybody else having this issue?

  3. Rick December 20, 2009 at 7:56 pm #

    YES! I am having the exact same problem. I am not sure if it is the tb server giving me the “all circuits are busy”, or the UM server. I am playing around with the settings right now. This article is good but seems to assume an awful lot instead of giving all instructions.

  4. Jonathan December 22, 2009 at 10:08 am #

    Sorry, I believe it was a typo. You should dial 8888 to access UM.

  5. Andy January 11, 2010 at 1:45 pm #

    Awesome, this article made it a breeze. Of course I always forget to apply the config changes on trixbox so it didn’t work the first time, but not this articles fault!

  6. Daniel June 16, 2010 at 7:30 pm #

    How is it possible to get the voicemail directed to my exchange box instead of Asterisk?

  7. Eusebio July 20, 2010 at 6:20 am #

    Been a while since anyone posted but thought I would add a comment. If anyone is having the ‘all circuits are busy error’ it is worth checking that your UM startup under Server Configuration – UM is set to TCP and that the DIal Plan uses unsecured.

  8. David August 4, 2011 at 9:17 am #

    Am I the only one that was unable to finish this configuration?
    I did as the artical described, using elastix and exchange 2010, I can dial to the server but I am getting the anoying ‘all circuits are busy’ error,
    I believe that the exchange server 2010 is not answering and the error comes after a time out, but I am not sure,
    can anyone help?


  9. Don October 3, 2011 at 10:45 am #

    Nope, me too. I get the following error on exchange though:
    The following UM IP gateways did not respond as expected to a SIP OPTIONS request.
    Transport = TCP, Address =, Port = 5060, Response Code = 0, Message = Unable to establish a connection.

    (replaced actual IP with – the actual IP works fine for SIP devices.)

  10. Don February 10, 2012 at 5:29 pm #

    so.. and I don’t mean to be a needy caller here.. but can we have some direction on issues we’re seeing?

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