Here are more lines from /var/log/freeswitch/freeswitch.log:
2014-02-14 14:27:05.079484 [DEBUG] mod_sofia.c:503 Channel sofia/vlan25/379 hanging up, cause: NORMAL_CLEARING
2014-02-14 14:27:05.079484 [DEBUG] mod_sofia.c:552 Sending BYE to sofia/vlan25/379
2014-02-14 14:27:05.079484 [DEBUG] switch_core_state_machine.c:48 sofia/vlan25/379 Standard HANGUP, cause: NORMAL_CLEARING
2014-02-14 14:27:05.079484 [DEBUG] switch_core_state_machine.c:667 (sofia/vlan25/379) State HANGUP going to sleep
2014-02-14 14:27:05.079484 [DEBUG] switch_core_state_machine.c:446 (sofia/vlan25/379) State Change CS_HANGUP -> CS_REPORTING
2014-02-14 14:27:05.079484 [DEBUG] switch_core_session.c:1287 Send signal sofia/vlan25/379 [BREAK]
2014-02-14 14:27:05.079484 [DEBUG] switch_core_state_machine.c:415 (sofia/vlan25/379) Running State Change CS_REPORTING
2014-02-14 14:27:05.079484 [DEBUG] switch_core_state_machine.c:749 (sofia/vlan25/379) State REPORTING
2014-02-14 14:27:05.079484 [DEBUG] switch_core_state_machine.c:92 sofia/vlan25/379 Standard REPORTING, cause: NORMAL_CLEARING
2014-02-14 14:27:05.079484 [DEBUG] switch_core_state_machine.c:749 (sofia/vlan25/379) State REPORTING going to sleep
2014-02-14 14:27:05.079484 [DEBUG] switch_core_state_machine.c:440 (sofia/vlan25/379) State Change CS_REPORTING -> CS_DESTROY
2014-02-14 14:27:05.079484 [DEBUG] switch_core_session.c:1287 Send signal sofia/vlan25/379 [BREAK]
2014-02-14 14:27:05.079484 [DEBUG] switch_core_session.c:1492 Session 131 (sofia/vlan25/379) Locked, Waiting on external entities
2014-02-14 14:27:05.079484 [NOTICE] switch_core_session.c:1510 Session 131 (sofia/vlan25/379) Ended
2014-02-14 14:27:05.079484 [NOTICE] switch_core_session.c:1514 Close Channel sofia/vlan25/379 [CS_DESTROY]
2014-02-14 14:27:05.079484 [DEBUG] switch_core_state_machine.c:556 (sofia/vlan25/379) Callstate Change HANGUP -> DOWN
2014-02-14 14:27:05.079484 [DEBUG] switch_core_state_machine.c:559 (sofia/vlan25/379) Running State Change CS_DESTROY
2014-02-14 14:27:05.079484 [DEBUG] switch_core_state_machine.c:569 (sofia/vlan25/379) State DESTROY
2014-02-14 14:27:05.079484 [DEBUG] mod_sofia.c:396 sofia/vlan25/379 SOFIA DESTROY
2014-02-14 14:27:05.079484 [DEBUG] switch_core_state_machine.c:99 sofia/vlan25/379 Standard DESTROY
2014-02-14 14:27:05.079484 [DEBUG] switch_core_state_machine.c:569 (sofia/vlan25/379) State DESTROY going to sleep