Hi I was seeing something similar using topos. All seemed to be ok until the far end (Asterisk) sent a BYE. At which point kamailo passed the message to WITHINDLG, in which loose_route came up false (-1) and the BYE got missed, falling through to the “404 Not here” at the end of WITHINDLG. .. I never did work out what caused it. However what I then did was start with the latest kamailo 5.4 cfg file and step forward adding my customisations back in, looking for what caused the issue. As you do with these things I cleaned my code up as I went. All I can say is that when I’d added everything back it was still working. Mark On 2 Aug 2020, at 11:46, mohsen khashei <mkhashei(a)gmail.com> wrote: Hi all. I use topoh module for topology hiding and this is my config for topoh: modparam("topoh", "mask_key", "my key") modparam("topoh", "mask_callid", 1) modparam("topoh", "callid_prefix", "!!:") modparam("topoh", "sanity_checks", 1) modparam("topoh", "mask_ip", "x.x.x.x") modparam("topoh", "uri_prefix_checks", 1) modparam("topoh", "uparam_name", "line") modparam("topoh", "uparam_prefix", "sr-") modparam("topoh", "vparam_name", "branch") modparam("topoh", "vparam_prefix", "z9hG4bKsr-") and also i use: modparam("dialog", "lreq_callee_headers", "TH: dlh\r\n") for dialog module. my calls come from asterisk and routed to the carrier(sip trunk) and vice versa, when i make a call from asterisk every thing works fine until the call hanged up from the carrier. at that modemt the kamailio send an 481 call/leg transaction does not exist. if call dropped bye the asterisk user everything works fine. how can i solve this? _______________________________________________ Kamailio (SER) - Users Mailing List sr-users(a)lists.kamailio.org https://lists.kamailio.org/cgi-bin/mailman/listinfo/sr-users -- Mark Boyce Dark Origins Ltd _______________________________________________ Kamailio (SER) - Users Mailing List sr-users(a)lists.kamailio.org https://lists.kamailio.org/cgi-bin/mailman/listinfo/sr-users