Hi Gaurav,
Device Mobility
-----------------------
It is common in multisite environments for some users to roam between sites on a regular basis. When such users take their Cisco Unified Communications endpoints with them, such as Cisco Unified Wireless IP Phones or Cisco IP Communicator (softphone) phones, the standard configuration of their endpoints needs to be adapted to suit the needs of the current physical location. This new feature of CUCM is called device mobility and it allows CUCM endpoints to dynamically reconfigure itself based on their actual location as determined by the IP address that is used by the device.
Unified mobility
-------------------------
This is for people who are on continuous roaming for business or other purposes, implementing unified mobility will let those users make and recieve calls on/from their personal cell phone.calls can be attended on IP Phone + other network phone at same time. Unfied mobility can be implemented in two ways:-
Mobile connect in which incoming cals to a user's desk phone can ring almost 10 remote destination numbers(PSTN phones usually) at the same time and the user can take the call from any of those phones.
Mobile Voice Access(MVA) in which a user can call an MVA number from his remote destination or even other PSTN phones and then make outbound calls to the PSTN phones making it look as if he is making outbound calls from his desk phone.
Check the following doc for configuration of both on CUCM
http://www.cisco.com/en/US/docs/voice_ip_comm/cucm/admin/4_2_3/ccmfeat/fsdevmob.pdf
http://www.cisco.com/en/US/docs/voice_ip_comm/cucm/admin/7_1_2/ccmfeat/fsmobmgr.html
Hope that helps
Regards
Nitesh
PS:Pl rate helpful posts
