Exchange 2010 includes the ability to add presence and IM integration right into the OWA experience. This adds a number of handy features:
- Presence for internal and federated OCS contacts
- Ability to start and maintain chat sessions directly from OWA
- OCS contact list integration, including add/remove contacts and groups
- Ability to control your presence state from OWA
Now for some screenshots…
Presence integration including context menu additions:


Chat window and the ability to control multiple simultaneous chat sessions:


Your presence and presence control:


Contact list integration with groups and presence (the contact list is in the left pane below your folders):


Installation and configuration was fairly straight forward, only a few items to point out. First of all, here’s the download link and link to documentation. Right now there’s a missing link in the documentation for a UCMA update for Windows 2008 R2. That update is part of the 968802 package here. All you need for this integration is to apply the UCMARedist.msp update to your Exchange 2010 server.
Now, a few things to point out in terms of the integration process. First, make sure to put the spaces in between each pair of characters in the IMCertificateSerialNumber web.config value. If you don’t the integration won’t work and you’ll get an error in your event log:
Log Name: Application
Source: MSExchange OWA
Date: 11/12/2009 11:36:28 AM
Event ID: 87
Task Category: InstantMessage
Level: Error
Keywords: Classic
User: N/A
Computer: excassrv1.corp.evangelyze.net
Description:
An exception was thrown while attempting to load the IM provider .dll file.
File: C:\Program Files\Microsoft\Exchange Server\V14\ClientAccess\OWA\bin\Microsoft.Rtc.UCWeb.dll
The local certificate specified was not found in the store for local computer.
Next, when you run the command to add the InstantMessagingType value to your OWA virtual directory (Get-OwaVirtualDirectory | Set-OwaVirtualDirectory -InstantMessagingType OCS
) you will get errors for any CAS servers that are not running Exchange 2010:
Property InstantMessagingType can't be set on this object because it requires the object to have version 0.10 (14.0.100.0) or later. The object's current version is 0.1 (8.0.535.0).
+ CategoryInfo : NotSpecified: (0:Int32) [Set-OwaVirtualDirectory], InvalidObjectOperationException
+ FullyQualifiedErrorId : 79956A7E,Microsoft.Exchange.Management.SystemConfigurationTasks.SetOwaVirtualDirectory
This can be safely ignored – the value will be set on Exchange 2010 servers. If you want to be sure just run get-owavirtualdirectory –server <Ex2010CASSrvName> |fl where <Ex2010CASSrvName> is the name of your Exchange 2010 CAS Server. Among the output you should see this: InstantMessagingType: Ocs
Lastly, the documentation doesn’t seem to be complete in the “Configure Office Communications Server” section. You’ll need to add the FQDN of the certificate that you specified in the web.config as a trusted host to your OCS environment. To do so, right click your pool and select Properties –> Front End Properties. Click the Host Authorization tab and then click Add. Add the FQDN of your CAS and check the “Throttle as server” and “Treat as authenticated” check boxes.

It will take a few minutes for your OCS front end(s) to pick up this change. Depending on your level of impatience (mine is high) You can force it by restarting the front end service but this will disconnect all your users from OCS, so do this with caution if you are working in a production environment.
Lastly, in case you’re curious which user agent this connection uses, here you go:

That should do it. The entire process took about 5 minutes and works perfectly.