Hi all, My scenario is as follows: I have All the CSCFs on the same IP using different ports. P-CSCF advertises a public IP. Rest of the nodes including I-CSCF and S-CSCF listen local only. Behavior: When an ACK or PRACK goes from P-CSCF to S-CSCF, the RURI changes such that alias parameter is removed. Hence, P-CSCF ends up sending PRACK and ACK on private IP of UE. Here's what the config looks like: #!define WITH_NAT Any hints? -- View this message in context: http://sip-router.1086192.n5.nabble.com/Kamailio-ims-nat-issue-PRACK-ACK-ru… Sent from the Users mailing list archive at Nabble.com.