These are the options for Telephony when configuring a user in Lync:
The user cannot make calls with audio and video.
The user can make only PC-to-PC audio or video calls.
The user can use the Lync Server 2010 infrastructure to route all incoming and outgoing calls. The user can also make PC-to-PC calls.
Remote call control
The user can use Lync Server 2010 to control the desktop phone, and can also make PC-to-PC calls.
Remote call control only
The user can use Lync Server 2010 to control the desktop phone, but this disables PC-to-PC audio calls, and only enables the user to control his PBX phone from Lync 2010 to make PC-to-phone calls.