[SR-Users] Auth credentials on ACK, 13.2.2.4

Hello, I am having difficulties with one of my SIP Trunk providers who insists that the dropped calls are my fault. Long story short, I send the final ACK for the INVITE 200 OK messages to the provider's SBC and 15% of the time the provider's SBC just drops the packet without any justification. I read through RFC 3261 and as near as I can tell, my packets conform to RFC3261. The only thing that seems to not conform is in " 13.2.2.4 2xx Responses" paragraph 4, sentence 4. " The ACK MUST contain the same credentials as the INVITE." I am using the UAC module to do authentification. How do I get UAC to add the same credentials to the ACK as it did to the INVITE ? I am using Kamailio as a load balancer ( module dispatcher ). Thanks in advance. David Here is my awesome failure route : failure_route[FAIL_ONE] { if ( t_check_status("401|407") ) { if ( isflagset(11) ) { t_reply("503", "Authentication failed"); break; } if (uac_auth()) { setflag(11); t_on_failure("FAIL_AUTH"); append_branch(); t_relay(); } } if (t_is_canceled()) { exit; } }