Setting the Office Communicator group policy TelephonyMode to 4 (RCC only - PC-to-PC calls disabled) is non-functional and a known bug

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.