Windows OS

Consider the following situation: You have a bandwidth starved branch office that has been configured with Office Communicator 2007 and remote call control of a 3rd party phone system. You want the users to be able to make calls with the 3rd party phone system with OCS, but you don't want precious bandwidth eaten up by PC-to-PC calls with Office Communicator.

Normally, you would enable option '4' for the TelephonyMode in a GPO for Office Communicator, but there is only one problem. This option is currently broken, and this effectively kills remote call control (RCC) on the user's computer. For now, the best advice is to tell users "don't do that", but you know it will happen by accident or on purpose because the option to do PC-to-PC calls will still be available if you unset the TelephonyMode.

I am hoping this is fixed in the July 2008 update, or it is on the radar to be fixed in the next set of patches for Office Communicator. It would be even better if Microsoft does a rollup and releases a brand new .MSI so we no longer have to use the original MSI package with the MSP patches.

I know it sounds counter intuitive to disable instant messaging in Communicator but some organizations may have legal or other reasons for disabling instant messaging inside Communicator 2007. You still get presence information and if you are using OC only for remote call control or VOIP, you might not need or want your employees using IM.

In the RTM version of Communicator 2007, it was not possible to disable IM, but with the new July 2008 update, you can!

Once the update is installed, you need to set a registry setting on the client machine. I am hoping they update the group policy .ADM files to include this new functionality (hint hint), so that I don't have to manually add this for my clients.

The registry setting in question:

DWORD value of "1", at location HKEY_CURRENT_USER\Software\Policies\Microsoft\Communicator\DisableIM.

Please note that without KB 954439 installed (the July 2008 Communicator update), the older versions of Communicator 2007 do not know about or obey the registry setting.

The KB article that describes how to disable the IM functionality is KB 954648, and is available online.

Also, somewhat related to this, is the Ethical Walls API example I wrote about here, and that related download is here. In that API example, it allows the administrator to place users into Organizational Units in Active Directory and to configure communication blocks between members of the different Organizational Units.

Update: KB 954439 updates the Communicator client to version 2.0.6362.76, and is online now as of 08-01-2008. You can request it from MS here.

Update 2: Updated registry key to proper location - thanks Russ W.