2 nodes in shared DB, node1 and node2 respectively with hostname node1.mydomain.org node2.mydomain.org the profile name is called mydomain.org which is shared by the 2 nodes. a user registers on node1 and wait calls. someone from external gateway call him, so user@node1.mydomain.org or user@node2.mydomain.org both it works well. but from user@mydomain.org it reaches the callee one time on three. my question is: can I avoid NAPTR SRV rules and replace it by a TCP load balancing server ? (if I use full TCP for SIP messages and UDP as normal after media negotiation) because it seems that NAPTR SRV work only if the caller proxy understands it. with a TCP load balancer I can avoid this, but not sure if it won't break the SIP protocol. Thanks Franck