CallManager 4.x for interoperability with Exchange UM is now officially supported.

 It will helps customers by not forcing an upgrade to CCM5+ and therefore locking the customer down to Cisco’s platform for a longer period of time. 

Additionally, Cisco Unity is now not the only large platform that will support CCM4 for a voice mail in the inbox experience.

More details at http://technet.microsoft.com/en-us/library/cc164342.aspx

This hotfix for Office Communicator - Update for Communicator 2007: October 24, 2008 will be required for those who will have OCS 2007 and OCS 2007 R2 integration.

 This update fixes the following issues:

• 958659 (http://support.microsoft.com/kb/958659/) When you use telephony mode=4, you can only manually set the URI information in Communicator 2007
• 957793 (http://support.microsoft.com/kb/957793/) A Communicator 2007 client is unusually slow at startup
• 956734 (http://support.microsoft.com/kb/956734/) The presence status of Communicator 2007 changes to "Away" for all Terminal Server users when one user locks the desktop on a Windows Server 2008-based computer

Microsoft officially annouces OCS R2, please read the details at http://www.microsoft.com/Presspass/press/2008/oct08/10-14OCSR2PR.mspx.

Take a look into the OCS Reskit and read about ABSConfig.exe.

Believe me, this tool gives us a hand on publishing AD contacts phone into OCS gal (one way, of course).

I promise a guide with screenshots, on how to do it 

Recently, working on integration with a gateway, I found that it could not recognize the + (E.164 format) sent by Mediation.
Also, the "From" headers for incoming calls from certain PBXs do not comply with RFC 3966.

This little "feature" make me having lots of problems to and from communications with OCS, with incorrect phone routing.

Well there is an August 2008, patch to address this issue, look here: http://support.microsoft.com/kb/952785/

 It should be installed on these roles:

• Standard Edition Server
• Enterprise Edition Server – Front End
• Proxy Server
• Director Server
• Edge Server
• Forwarding Proxy

In order to config Mediation Server to strip the +, you have to install the patch and it should exist file:

MediationServerSvc.exe.config

 located at

C:\Program Files\Microsoft Office Communications Server 2007\Mediation Server

with the following content:

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
                 <appSettings>
                                <add key="RemovePlusFromRequestURI" value="Yes" />
                 </appSettings>
</configuration>

Is also possible to strip the + and enable TLS for, by changing the file to:

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
                 <appSettings>
                                <add key="RemovePlusFromRequestURI" value="Yes" />
                                <add key="GatewayTls" value="On" />
                                <add key="GatewayFqdn" value="gateway.domain.com" />
                 </appSettings>
</configuration>

This saved me a lot of work...

This error, has been bugging me for a long time.

In the past I managed to solve it by applying the instructions on this kb: http://support.microsoft.com/kb/896861

However I felt it was not "fully supported" for OCS. Well I was mistake, since recently I spotted this other article: http://technet.microsoft.com/en-us/library/bb663688.aspx, but exactly for OCS!

 Well, I'm happy!