If I understand you correctly, you want the agents to b able to sit at any desk and use any desk phone (IP Phone).   If that is true,  use the Extension Mobility feature  - it is like a Hotel, check in and check out.   On the desk phone : check box--> for Enable Extension Mobility. In Device--> Device Settings--> Phone Settings - you will need to add Phone login/logout Service.  (you will need to consult your documentation on what is needed here).   Then for each person create a User Defined Profile (UDP).  Device--> Device Settings--> Device Profile. Fill in a few of the fields at the top (most can stay as default). Top area of UDP device--> Pull down menu choose Subscribe / UnSubscribe Services and look for that Phone Login/Logout Service you created above to add.  This by the way has to be added to both the UDP for user and the desk phone. In Left Panel add the extension and normal extension information for your environment.  Note when creating the UDP , the field User Device Name,  think about how you want to name it for easy lookup later, if you multi locations, etc.   Then in the User Management  associate that UDP device  to that person/ user. Add a PIN for the user (required) and I add the extension down - if the are an Agent you need to also add the extension ot IPCC extension field..  Note when creating the UDP , the field User Device Name,  think about how you want to name it for easy lookup later, if you multi locations, etc. The user will use the Services button on the desk phone  to find the login/logout Service  and will need to enter in userID and PIN,  the phone will reset and the users' extension will take over the phone, they will also need to logout via that same Services button on Phone (well Services button is what is on several phones, but you may need to research you type of phone to see where they put that)   hope that helps if my assumption on what you were trying to achieve was correct. Otherwise,,, nevermind :-) ... View more