A customer of mine is using Lync with Cisco Cups for RCC. Now there is a problem with call forwarding. When a user set forwarding on the lync client the forwarding is set on the Cisco phone as expected. However when you disable call forwarding on the phone, the Lync client is not updated. So if you look at the problem you would conclude that Lync is pushing its settings to Cisco, but Cisco cannot update the settings in Lync. It seems to be by design, as i have tested with multiple deployment of Lync and OCS which are using RCC.
Now this can cause some problems. For example; a user logs of the laptop and enables call forwarding on his Cisco phone to forward calls to his cell phone. The user comes home and starts his laptop to continue some work from home. The Lync client starts and removes the call forwarding on the cisco phone, because the client has no forwarding set. As a result the calls are no longer forwarded to the user's cell phone as intended.
Now as it seems to be like design, the only workable options is to remove the forwarding option within lync in which the forwarding is no longer updated on the Cisco phones. Is there a way in which we can disable lync from updating the call forwarding in Cisco?
Answers provided are coming from personal experience, and come with no warranty of success. I as everybody else do make mistakes.