Office Communicator - Cannot connect to the phone system. The call control server may be temporarily unavailable. If the problem persists, please contact your system administrator. OCS 2007 R2 / Nortel CS1000. Reallocated a couple of Nortel 1220 desk phones to new users in a RNPG / Hunt Group. Phones working normally, can see contacts and presence in OCS, but both users are seeing the above error in OCS. Both have been setup for Remote Call Control in OCS but this does not work. Have checked and compared CS1000 and OCS settings but can't find anything. Fairly new to all this so any advice or suggestions most welcome.