Hanging Asterisk 1.6.2.13

Hi all,
in the last days my Asterisk PBX stops and keeps on hanging without accepting any connection.
The only thing working correctly is the console (rasterisk) and I must kill the process to be able to restart.
When it stops, I can read the following error message:

“chan_sip.c:3831 retrans_pkt: Maximum retries exceeded on transmission 3c26761421a1-6xlednwj49bq
for seqno 2 (Critical Response) – See doc/sip-retransmit.txt.”

Anyone can help?

Thanks a lot,

If you follow the instructions in that message, you will see that it is a secondary symptom and not much use in its own right.

Make sure you are compiled with no optimisation and with thread debugging enabled. The next time it stalls, use core show locks to see if there is a deadlock. Also consider using gcore to force a core dump and get a backtrace.