Core was generated by `/usr/sbin/asterisk -f -vvvg -c'.
Program terminated with signal 6, Aborted.
#0  0x00591402 in __kernel_vsyscall ()
(gdb) bt
#0  0x00591402 in __kernel_vsyscall ()
#1  0x00174ba0 in raise () from /lib/libc.so.6
#2  0x001764b1 in abort () from /lib/libc.so.6
#3  0x001aadfb in __libc_message () from /lib/libc.so.6
#4  0x001b1126 in malloc_consolidate () from /lib/libc.so.6
#5  0x001b2cfd in _int_malloc () from /lib/libc.so.6
#6  0x001b3ffd in calloc () from /lib/libc.so.6
#7  0x008482c3 in sip_alloc (callid=0x0, sin=0x6, useglobal_nat=12762, intended_method=5)
    at /usr/src/asterisk-1.4.18/include/asterisk/utils.h:359
#8  0x0088ac76 in sipsock_read (id=0x863b7d8, fd=14, events=1, ignore=0x0) at chan_sip.c:4598
#9  0x080a95d0 in ast_io_wait (ioc=0x8639ab0, howlong=1000) at io.c:279
#10 0x00866569 in do_monitor (data=0x0) at chan_sip.c:15601
#11 0x080f8f4b in dummy_start (data=0x863e2a8) at utils.c:852
#12 0x002c245b in start_thread () from /lib/libpthread.so.0
#13 0x0021a24e in clone () from /lib/libc.so.6