Hi,
we have 2 SIP servers. When INVITE is sent from one server to an account on the other server, ACK is not delivered.
Proxy branch is with setRecordRoute(true) and required Route header is in ACK request received by server. Server tries to deliver received ACK request directly to client (IP address in request URI), but not to the second server defined in Route header.
Finaly it is terminated by SocketTimeoutException and ACK request is dropped. BYE request leads to the same result.
Relevat part of system.log is attached.