Earlier parts in this blog have talked about VoIP, configured AsteriskNOW software PBX and configured inbound and outbound calls via the PBX. Now it is time to configure voicemail to be provided by Exchange Server and for the telephone users to be able to call Exchange an listen to their voicemail. In addition to listening to voicemail, when a user logs into Exchange via their telephone handset Exchange can read and the user change items in their mailbox (i.e. delete email, change calendar bookings) and direct calls to other users.
This blog article will look specifically at Exchange Server 2010. The following article will repeat the steps here, but for Exchange Server 2013. So lets start by configuring all the required pieces on the Exchange Server.
Configuring Exchange Server 2010 Unified Messaging
The first thing to set up in Exchange Server 2010 is to ensure that you have the Unified Messaging role installed on at least one Exchange Server. This role can be shared with any other role apart from the Edge Server role is you need to. Once the role is installed go to the Unified Messaging area under Organization Configuration in EMC.
By default Exchange is installed with the United States language pack. Download and install the correct unified messaging language packs for your country. These are service pack dependent, so install the correct one.
For Exchange 2010 create a UM Dial Plan with the correct number of digits (four in the case of this blog), set Unsecured for VoIP Security and enter your Country/Region code (44 for the UK).
Click Next and associate the server on which you installed the UM role with this dialplan.
In the UM IP Gateways dialog add a gateway for the IP address of your PBX. Exchange requires TCP support and we covered the steps for configuring Asterisk in Step 3 to support SIP over TCP.
If you are using a PBX that supports custom ports for SIP over TCP (Asterisk 1.8 does not support this for TCP) then remember to adjust the port in Exchange Server. You set the port if different from 5060 using Exchange Management Shell: Set-UMIPGateway –identity BlogGateway -Port 5065 for example.
The application event log will show if there are errors in the IP Gateway configuration. If there are no errors and Exchange is able to communicate successfully with your PBX over TCP then it will report Event ID 1401
The following UM IP gateways responded promptly to a SIP OPTIONS request.
Transport = TCP, Address = 192.168.5.100, Port = 5060, Response Code = 200, Message = OK
If you change your view to the UM Mailbox Policies tab then you can see the default mailbox policy that has been created for you. You might want to change this, but at the very least you need to check its settings. For a lab environment I suggest a 4 character PIN, no PIN lifetime and 1 previous PINs to disallow.
For now you do not need to create a UM Auto Attendant and so we will skip this section of the configuration for you to return to in your own time later.
Now that you have the initial configuration complete, go back to the UM Dial Plans tab and open the dial plan that you created earlier. You will need to associated a subscriber access number with this dial plan. This is the number that users will call to listen to their voicemail. Exchange Server will be informed of the dialled number when the PBX forwards the call to it, and so the number called must be associated with a mailbox or be the subscriber number. In other PBX systems, this number is often called the Pilot Number. In the lab we are building here, with a four digit dial plan, the chosen subscriber number is 8000:
Finish the remaining tabs in this dialog by entering valid Dial Codes and other options as you need to:
Change to Server Configuration > Unified Messaging in the Exchange Management Console and double-click your unified messaging server. Ensure the UM Settings properties reads TCP for startup mode and if you change this ensure that you restart the Microsoft Exchange Unified Messaging service.
The next blog post will cover these settings for Exchange Server 2013 and then the two following will look at the mailbox configuration and the configuration on the PBX to create the trunks to reach Exchange Server and the settings to forward voicemail messages to the Exchange Server.