The prerequisites to installing an R1 CWA server in an R2 SIP environment you first need to create a UC certificate with the necessary subject name and subject alternate names. Then create a 32 bit Windows Server with Service Pack 2 or above and of course the Office Communication Server 2007 code, and a BES server 4.7 and above. 　　　To integrate Blackberry Enablement Services (BES) with Office Communication Server 2007 R2 you first need to do a Forest Prep, Domain Prep with the R1 code. In this prep you are preparing the SIP domain to except the install of an Office Communication server 2007 R1 Role into an Office Communication server 2007 R2 domain environment. You then need a 32 bit Windows Server installed with service pack 2 and above, then using the R1 code you can click setup, then Other Roles, then Communicator Web Access role and install that role on the 32 bit Windows Server.

On the BES server it first must be installed with the 4.7 and above BES code and you must then install the Collaboration Services on the BES server and make sure the services are started.　Through the BES server menu you navigate to the Collaboration Service and in the server or URL text space type in the subject name or one of the subject alternate names in the certificate along with a DNS "A" record setting for the name used.

The reason for this article is because if the R1 forest and domain prep is not done you cannot in install the R1 CWA role. You will get an error that the forest prep is reading "partial" and the role will not install.