Hello, Not knowing about this particular issues, but I would suggest to update at least to the latest 5.3.x release (5.3.9) as there might be important bug fixes. Cheers, Henning From: sr-users <sr-users-bounces(a)lists.kamailio.org> On Behalf Of Eugene B Sent: Friday, February 11, 2022 10:24 AM To: sr-users(a)lists.kamailio.org Subject: [SR-Users] resending same message from UE after receiving RP-ACK Hi, I trying to use smsops module as SMSC. When I sending message from UE I see re-sending same message after each RP-ACK(~10 attempt). What could be the problem? Thanks! pcap in attach. kamailio 5.3.2 -- Yours faithfully, Eugene B.