Am 09.03.2012 20:56, schrieb Giacomo Vacca:
One of the solutions I’ve found is using always add_contact_alias() in onreply_route when handling the 200 OK, and then use handle_ruri_alias() when defining the destination for the ACK.

Yes, that the pragmatic approach I always use. IMO it is also a bit of security. I do not like to blindly trust user provided data (e.g. contact header), thus I always use the IP:port from where the message was received.

regards
Klaus