For those whom had walk through the evolution of Office Communications Server 2007/2007 R2, a lot of those were wondering: where had the Communicator Web Access (CWA) went to? Basically it hasn’t went anywhere, just that it has been now ‘merged’ together with Exchange Outlook Web App (OWA). I see this as a advantage to most customers where you’ve a single console for both mail and also instant messaging, truely Unified way to Communicate! Not to mention reducing the additional role on Lync just to have this featured enabled.

To get started, download these components:

  1. Microsoft .NET Framework 3.5 (if your Exchange 2010 SP1 is running on Windows Server 2008) –
  2. Unified Communications Managed API 2.0, Core Runtime (64-bit) –
  3. For Exchange 2010 SP1 Client Access Server Role on Windows Server 2008 KB 2647091 Unified Communications Managed API 2.0 Redist (64 Bit) Hotfix –
  4. KB 968802 Microsoft Office Communications Server 2007 R2 Hotfix –
  5. Microsoft Office Communications Server 2007 R2 Web Service Provider –
  6. KB 981256 OCS 2007 R2 Web Service Provider Hotfix –

Once you’ve all these downloaded and install the files in the listed sequence:

It took me about an hour just to figure out the links and also the sequence of installation, so for readers who often visit my blog site – you’re in luck!😉

Unified Communications Managed API 2.0, Core Runtime (64-bit) would detect and install if Windows Media Service is not present. The system would reboot itself after the installation and you would need to reinitiate the installation once more get Unified Communications Managed API 2.0, Core Runtime (64-bit) installed.

After the installation of UCMA and also hotfix applied, go to the Control Panel > Programs & Features to confirm that theMicrosoft Unified Communications Managed API, Core Runtime 64-bit is installed with the version on 3.5.6907.244.

Proceed with the remaining OCS 2007 R2 Web Service provider and the hotfix; to confirm the installation is successful:

  • Open the register editor (regedit) and look for HKLM\SYSTEM\CurrentControlSet\Services\MSExchange OWA\InstantMessaging\ImplementationDLLPath. The value displayed should be <Exchange Install Path>\ClientAccess\owa\bin\Microsoft.Rtc.UCWeb.dll
  • Copy the path above and make sure the Microsoft.Rtc.UCWeb.dll exist in the folder

Now, let’s proceed to run the configurations on the Exchange CAS Server Role:

  1. Launch the Exchange Management Shall (EMS) and type in the following command: Get-ExchangeCertificate|fl Services,Thumbprint. Copy the thumbprint that has the IIS service listed
  2. Run the next command to enable Instant Messaging onto the OWA Virtual Directory: Get-OwaVirtualDirectory | Set-OwaVirtualDirectory -InstantMessagingType OCS -InstantMessagingEnabled:$true –InstantMessagingCertificateThumbprint [PasteYourCertificateThumbPrintOnStep1] -InstantMessagingServerName LyncPoolFQDN
  3. Type IISreset and wait for the services to be restarted

On the Lync Server

  1. Launch the Lync Topology Builder and select the option to Download topology from existing deployment
  2. Expand the Site Name and locate the Trusted Application Servers. Right click to create a new Trusted Application Pool
  3. Here’s the tricky part, at this step, a lot of people may have just put in the Exchange Server CAS FQDN; this is not exactly the correct way – you’ll need to cross check on the Subject Name (SN) on the certificate that is assigned to the Exchange IIS services. In some cases, some would use the internal Microsoft CA Services and some would use 3rd party SSL certificates. For my case, I’d placed the public domain that is being used to access the Outlook WebApp service (e.g. . Select Single Computer Pool and click Next
  4. Select the Pool Server name at the Next Hop Pool option and click on Next
  5. Complete the wizard by publishing the changes; if you’re using a public name instead of the actual Exchange FQDN, you’ll receive a warning that the published name is not registered in the Active Directory objects. Ignore the message and proceed to the next step
  6. Open the Lync Management Shell
  7. Type in netstat -a | findstr 5059, make sure that the server is not using this port as we’ll be fixing this port that OWA and Lync would be interacting with each other
  8. Take note, this is another tricky step, you would need to use the Certificate Subject Name (SN) that was initiall created under the Trusted Application Pool. Type the following command: New-CsTrustedApplication -ApplicationId ExchangeOWA -TrustedApplicationPoolFqdn <Certificate Subject Name>-Port 5059
  9. Publish the topolgy: Enable-CsTopology

We’re now almost done, open the web browser from any of the endpoints and login to OWA and you should get the Lync Instant Messaging function enabled: