(gdb) bt
#0  0xa7f8e01d in udp_socket_set_them (info=0x0, them=0xa658537c) at udp.c:270
#1  0xa7f6a41b in opbx_rtp_set_peer (rtp=0x80b1f80, them=0xa6585aa4) at rtp.c:1393
#2  0xa65bc7de in process_sdp (p=0x80af358, req=0xa6587b10) at chan_sip.c:4328
#3  0xa65c45a1 in handle_response_invite (p=0x80af358, resp=183, rest=<value optimized out>,
    req=0xa6587b10, ignore=0, seqno=103) at chan_sip.c:10804
#4  0xa65dcd06 in handle_response (p=0x80af358, resp=183, rest=0xa6587d34 "Session Progress",
    req=0xa6587b10, ignore=0, seqno=103) at chan_sip.c:11170
#5  0xa65dde5c in handle_request (p=0x80af358, req=0xa6587b10, sin=0xa6588eb8, recount=0xa6588ecc,
    nounlock=0xa6588ed0) at chan_sip.c:12401
#6  0xa65def5d in sipsock_read (id=0x807f0d0, fd=11, events=1, ignore=0x0) at chan_sip.c:12630
#7  0xa7f1e394 in opbx_io_wait (ioc=0x806ac60, howlong=1000) at io.c:287
#8  0xa65d69bd in do_monitor (data=0x0) at chan_sip.c:12814
#9  0xa7eac0bd in start_thread () from /lib/tls/libpthread.so.0
#10 0xa7cdf8fe in clone () from /lib/tls/libc.so.6
(gdb)