Pro-Exchange,Lync & Office 365
Belgian Microsoft Unified Communications Professionals
Microsoft Exchange Server, Microsoft Lync Server & Office 365
Installation of OCS 2007 R2 Web Service Provider for Exchange 2010 RTM

IMPORTANT UPDATE : Exchange 2010 SP1 article can be found here :

First of all, you have to download the bits here:

Then install the MSI file on the Exchange 2010 CAS Server(s), this will extract 4 installation files into a directory on the server.


Open the installation folder

Note that you have to download a hotfix for UcmaRedist.msi if you are running Windows 2008 R2
(Part of the OCS oktober 2009 update : UcmaRedist.msp)


You must install the files in the following order:

  • vcredist_x64.exe
  • UcmaRedist.msi
  • UcmaRedist.msp

Now you need to get Certificate Information for Exchange
Note : The Client Access Server must be configured to use a certificate which is trusted by OCS 2007 R2
(This means that it requires a none self singed certificate!)

You must get the following information for the Certificate on the Exchange 2010 CAS Server :

  • The Certificate Issuer
  • Certificate Serial number

Type Get-ExchangeCertificate and use the format list output to view all information (Get-ExchangeCertificate | fl)
Note : You need the Certificate that is configured for IIS


Find the web.config file on the Exchange CAS Server
Located here by default : C:\Program Files\Microsoft\Exchange Server\V14\ClientAccess\Owa


Edit the following values:

  • IMPoolName (which must reflect the FQDN of your OCS Front-End server
  • IMCertificateIssuer (which must have the CN of the Issuer)
  • IMCertificateSerialNumber (which must be the serial number  and you must manually add spaces in the Serial Number string to separate each octet)


Now you must enable OCS Presence Integration with the following command:
(Get-OwaVirtualDirectory –server <YOUR_EXCHANGE_CAS_SERVER>).Identity | Set-OwaVirtualDirectory –InstantMessagingType OCS


Now you should restart the IIS Server


If the Windows Firewall is enabled on a Client Access Server running Windows Server 2008, you may need to add an exception to allow OCS 2007 R2 to communicate with the Client Access Server

On the left side of the Windows Firewall window, click “Allow a program through Windows Firewall”
Add the IIS Worker Process (“C:\Windows\System32\inetsrv\w3wp.exe”)



Exchange 2010 CAS Configuration is completed
Now OCS Configuration on the Front-End server must be configured

The Exchange Server 2010 Outlook Web Access IM Integration component is implemented as an OCS 2007 end-point. In order for the integration component to be able to sign-in to OCS 2007 R2 it is necessary to configure the OCS 2007 R2 server to trust the Exchange Client Access Server. This is configured by adding the Exchange Client Access Server as a trusted server on the OCS 2007 R2

Open the Front-End Properties of the Pool in Office Communications Server 2007 R2 management console and open the Host Authorization Tab


Add the Exchange server as an Authorized Host:

  • Add the FQDN of the Exchange 2010 CAS Server
  • Select Throttle As Server
  • Select Treat as Authenticated


You should see an entry similar to this one


Now that you have configured the OCS Front-End Server you need to restart the Front-End Service on the OCS Server


Now you are done configuring the integration :)


Presence integration in Outlook Web App screenshot


Posted 11-16-2009 1:15 by Johan Delimon


Exchange 2010 wrote Installation of OCS 2007 R2 Web Service Provider for Exchange 2010 SP1
on 09-01-2010 2:49

IMPORTANT : Exchange 2010 RTM article can be found here :