Vimod,
Have you tried the latest version of Cisco IP Communicator? I just did a test here with version 8.6.2.0 with no problem calling both direction.
If you still have problem, could you please send the softphone.log to
jabbersdk-support@cisco.comYou can find it at the following locations:-
Windows XP C:\Documents and Settings\{username}\Local Settings\Application Data\softphone.log
Windows 7/Vista C:\Users\{username}\Application Data\Local\softphone.log
Mac OS X /Users/{username}/Library/Application Support/softphone.log
Howard