[SR-Users] ACK / BYE transaction problem

Hi all Follow scenario Class5 system [c5] --> Loadbalancer kamailio (dispatcher module) [lbl] ---> gateway kamailio [gw] --> carrier [carr] I get Invites from [c5] with Request ,To, from, contact, pid in national format 0794445566 [lbl] dispatches this to [gw] For the [carr] I need international format. So doing these transactions in [gw] And sending to [carr] in international format Request, to, from, contact, ... => 417794445566 Everything ok Then I get a 100, 183 and even 200 from [carr] Ack is coming from [c5] to [lbl] and [gw] - but then it stocks The ACK is not sent to the [carr] I kamailio log I see DEBUG: RFC3261 transaction matching failed DEBUG: t_lookup_request: no transaction found So for me, the ACK cannot be assigned to a transaction and gets discarded by if ( is_method("ACK") ) { xlog(,"L_INFO", "WITHINDLG ACK - not loose route\n"); if ( t_check_trans() ) { xlog(,"L_INFO", "WITHINDLG ACK - t_check_trans() \n"); # no loose-route, but stateful ACK; # must be an ACK after a 487 # or e.g. 404 from upstream server t_relay(); exit; } else { xlog(,"L_INFO", "WITHINDLG ACK - not t_check_trans() DISCARD!!\n"); # ACK without matching transaction ... ignore and discard route(NATMANAGE); #t_relay(); #exit; Any idea? Problem with modifying the sip tags? Or problem with the dialog? Thanks for helping OIi