Thanks Daniel, I will look into that. Indeed I found the logic that corrects the time ticks for any drifting, using the time of day. I guess that causes the registrations to expire.  I am out of the office for a couple of days, but will get back to you.  Best Regards, Erik  Hello, On 15/02/2017 14:47, Erik Visser wrote: kamailio is using unixtime for registrations, not relative time. But the timer callbacks are using relative intervals to know when to be executed (e.g., timer callbacks are defined to be executed like very 1 minute, or every 90 seconds). It may be that some of the timers try to catch up on missed intervals. It is strange that you say no sip traffic is processed. Can you simulate again the situation and get the backtrace with gdb from few sip workers? If your traffic is over udp, then do 'kamctl ps', get the pid of processes with index 1, 2 and 3, then use gdb to attach to those PIDs and grab the output of: bt full info locals list Cheers, Daniel -- Daniel-Constantin Mierla www.twitter.com/miconda -- www.linkedin.com/in/miconda Kamailio Advanced Training - Mar 6-8 (Europe) and Mar 20-22 (USA) - www.asipto.com Kamailio World Conference - May 8-10, 2017 - www.kamailioworld.com