The interesting part is quoted below, if you turn on some sofia debug, I suspect you will see some errors such as a remote icmp reject.

On Feb 25, 2014, at 8:40 AM, vinay <vinaysaini.1091@gmail.com> wrote:

    2014-02-25 00:10:45.103685 [DEBUG] switch_core_session.c:1048 Send signal sofia/sipinterface_1/+918146234576@sip.sipnl.net [BREAK]
    2014-02-25 00:10:45.103685 [DEBUG] sofia.c:5889 Channel sofia/sipinterface_1/+918146234576@sip.sipnl.net entering state [calling][0]
    2014-02-25 00:10:45.103685 [DEBUG] switch_core_session.c:1048 Send signal sofia/sipinterface_1/+918146234576@sip.sipnl.net [BREAK]
    2014-02-25 00:10:45.103685 [DEBUG] switch_core_session.c:1048 Send signal sofia/sipinterface_1/+918146234576@sip.sipnl.net [BREAK]
    2014-02-25 00:10:45.103685 [DEBUG] switch_core_session.c:1048 Send signal sofia/sipinterface_1/+918146234576@sip.sipnl.net [BREAK]
    2014-02-25 00:10:45.103685 [DEBUG] sofia.c:5889 Channel sofia/sipinterface_1/+918146234576@sip.sipnl.net entering state [terminated][503]
    2014-02-25 00:10:45.103685 [NOTICE] sofia.c:6733 Hangup sofia/sipinterface_1/+918146234576@sip.sipnl.net [CS_CONSUME_MEDIA] [NORMAL_TEMPORARY_FAILURE]