To have both of them work together, you need to have Exchange Server 2007 SP1. Here are the key steps that you need to perform to configure them:
- Configure the new dial plan. To do this, run this command from the powershell: New-umdialplan -name OCSPlan -Uritype "Sipname" -Voipsecurity "SipSecured" -Numberofdigitsinextension 4
- Go to properties of this dial plan and set the subscriber access number. Subscriber access is used by users to access their individual mailboxes to retrieve e-mail, voice messages, contacts, and calendaring information. Outlook Voice Access is the new Exchange 2007 Unified Messaging feature that lets subscribers access their Exchange 2007 mailbox.
- Apply this dial plan to the UM server: set-umserver -id UM_Server_Name -dialplans OCSPlan
- Run Powershell script "EXCHUCUTIL.PS1" from Exchange Management Shell. This is installed when you apply SP1 for Exchange 2007. To run this successfully you might need to modify the properties of the Start Menu shortcut for the Exchange Management Shell so that it launches directly from the Scripts folder "Program files\Microsoft\Exchange Server\Scripts".
- On the OCS server, run OCSumutil with the following command line: ocsumutil /domain:yourdomain.com
Now you can configure your users for Unified Messaging. You can do this from Exchange Management Console and right click on the user to Enable Unified Messaging and select the dial plan.So now when you log on with this user to Communicator 2007, you will see the additional call menu from where you can forward your calls or redirect incoming calls to voicemail.
And now you get a Missed Conversation notification when someone IMs you and you are offline or away:
Also, You get the missed call notifications or voice mails when someone calls you via OCS client: