Currently each and every SameTime Client manages it's wherever detected location in a local table with in eclipse workspace.
The detection is bound to the MAC address of the respective default gateway (router).
So every user in the deployment will be asked to type in the same information to identify i.e. the branch location.
Please set up a server side service to keep all the location information ascertained by the users in a central database,
so that the next user may benefit from it.
Also make this service manageable for Admins to pre configure the location information for the enterprise gateways prior to roll out.
Google location service also might be worth while giving a thought in the context...