OCS 2007 R2 interop with Server 2008 R2

OCS 2007 R2 has not been supported on Windows server 2008 R2 for some time now.
But Microsoft have released two Knowledge base articles that show some progress to having OCS 2007 R2 running on the 2008 R 2 platform.
When Windows Server 2008 R2 was released many people wanted to migrate to the latest version of the OS. But the problem was that Office Communications Server 2007 R2, OCS 2007 or LCS 2005 did not work correctly after  upgrading to Windows Server 2008 R2 in a domain environment.

Microsoft have released Knowledge Base Article 982020 detailing a resolution to this problem.

Additionally there were problems on using the os as host servers for OCS 2007 R2 in a member server role.
Knowledge base article 982021 describes how to implement OCS R2  using Windows Server 2008 R2 and details the security changes, hotfixes and fixes in a step by step format, very useful.