Hi we are currently deploying Exchange 2007 UM and OCS. The integration between the two seems to work correctly since I have access to voice mail and I can receive vocal message in my Exchange mail account. But I can not use the extension I have define for the AA or the user or the hung group I created from a Communicator (I can access to the AA with the SIP address created with OcsUMUtil.exe). I think a proper routing has to be created but I do not know what I must route and where since on OCS we can only route to mediation server.