Hi, There are UAs and gateways out there which construct the ACK incorrectly and always set the domain of the RURI to the next hop. Does the Request URI of the ACK match the remote Contact in the 200 OK? On Mon, May 14, 2018 at 09:39:44PM +0300, Sergey Safarov wrote: stored -- Alex Balashov | Principal | Evariste Systems LLC Tel: +1-706-510-6800 <(706)%20510-6800> / +1-800-250-5920 <(800)%20250-5920> (toll-free) Web: http://www.evaristesys.com/, http://www.csrpswitch.com/ _______________________________________________ Kamailio (SER) - Users Mailing List sr-users(a)lists.kamailio.org https://lists.kamailio.org/cgi-bin/mailman/listinfo/sr-users

Hi Ssergey, the ACK seem OK, but the R-URI does not contain the "sip.instance" parameter defined in the 200 OK's Contact. Usually all contact parameter should be preserved when constructing the ACK R-URI. Does your server receive the ACK, but it is not able to forward it back to the callee (if yes, do you see any ERROR in the logs) ?

Daniel On 05/14/2018 08:39 PM, Sergey Safarov wrote: Hello I have a call with not passed ACK by Kamailio. http://prntscr.com/jhtobo Same behaviour i looked before when SIP endpoint contact string is wrong In this call look as contact string correct is correct (packets 7 and 8) and i not understand why ACK (packet 9) not passed to callee. Could you help me understand this. PCAP file is create using homer tracer and TCP transport packets is stored as UDP. Sergey _______________________________________________ Kamailio (SER) - Users Mailing Listsr-users@lists.kamailio.orghttps://lists.kamailio.org/cgi-bin/mailman/listinfo/sr-users