I believe this bug describes asterisk bug #17255 : https://issues.asterisk.org/view.php?id=17255
It would seem that after some SIP calls, udp sockets are not closed. If left running too long, you may see the following in asterisk's log ( a few million times a minute ) : [2011-08-09 09:20:02.775] ERROR[5081] res_timing_timerfd.c: Read error: Bad file descriptor [2011-08-09 09:20:02.775] DEBUG[5081] res_timing_timerfd.c: Expected to acknowledge 1 ticks but got 0 instead [2011-08-09 09:20:02.775] ERROR[5081] res_timing_timerfd.c: Read error: Bad file descriptor [2011-08-09 09:20:02.775] DEBUG[5081] res_timing_timerfd.c: Expected to acknowledge 1 ticks but got 0 instead [2011-08-09 09:20:02.775] ERROR[5081] res_timing_timerfd.c: Read error: Bad file descriptor [2011-08-09 09:20:02.775] DEBUG[5081] res_timing_timerfd.c: Expected to acknowledge 1 ticks but got 0 instead [2011-08-09 09:20:02.775] ERROR[5081] res_timing_timerfd.c: Read error: Bad file descriptor [2011-08-09 09:20:02.775] DEBUG[5081] res_timing_timerfd.c: Expected to acknowledge 1 ticks but got 0 instead [2011-08-09 09:20:02.775] ERROR[5081] res_timing_timerfd.c: Read error: Bad file descriptor [2011-08-09 09:20:02.775] DEBUG[5081] res_timing_timerfd.c: Expected to acknowledge 1 ticks but got 0 instead The resource exhaustion eventually leads to Asterisk being unable to function as it will either run out of UDP sockets or return errors about open files. root@ast-1:/var/log/asterisk# lsof | grep asterisk | grep UDP | wc 121 1089 11004 It has 121 sockets open, but only one call in progress. Running asterisk : Connected to Asterisk 1.6.2.5-0ubuntu1.4 currently running on pri1 (pid = 5132) ** Bug watch added: Asterisk Issue Tracker #17255 https://issues.asterisk.org/view.php?id=17255 ** Also affects: asterisk via https://issues.asterisk.org/view.php?id=17255 Importance: Unknown Status: Unknown ** This bug has been flagged as a security vulnerability -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/816287 Title: Asterisk UDP ports not freed/ports leaking [ upstream patch available ] To manage notifications about this bug go to: https://bugs.launchpad.net/asterisk/+bug/816287/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs