If I understood it right, EM (Extension Mobility) should be treated like a "physical phone" in your scenario. Let's take a look at some use cases of EM:
Case 1:
A directory number (DN) is only associated (configured) on EM profile. The DN was not configured on any physical phone (e.g. 7940/7960 phones). You configure "owner ID" on the EM profile like you configure it on a physical phone.
Before EM login, your phone does not exist. You won't be able to use Unified Mobility(UM) without an IP phone.
After EM login, there's only one IP phone exists. This IP phone has the owner ID configured on it. UM works fine.
Case 2:
A directory number (DN) is associated (configured) on EM profile and a physical phone (let say phone A). You have to configure Owner ID on phone A, EM Profile, or both.
Before EM login, only phone A would be considered as your IP phone. Owner ID has to be configured on phone A to get UM worked.
After you logged in EM on phone B, you have two IP phones (A and B) with the Owner ID. UM works like you have two physical phone with the same Owner ID.
Case 3:
Different DNs were assiged to EM profile and physical phone. Same Owner ID was associated to those. It's like you have different physical phones with different DNs. UM still works.
Michael
http://htluo.blogspot.com
