[OpenSER-Users] force_tcp_alias

There are numerous discussion on using force_tcp_alias() in order to route all SIP requests over an already established TCP between the client and OpenSER, however, I cannot make it work. What I would like to accomplish, any client registering using TCP should have all SIP requests sent towards the client using the already established TCP and not routed based on the Contact header used during REGISTER. Reading posts it would seem that putting force_tcp_alias(); within the route{ } should do the trick. However, this doesn't seem to do the trick for me, SIP requests towards the client are still routed using the Contact information and for example a SIP MESSAGE is sent over UDP from OpenSER towards the client using the information in the Conatct header. Any hints what to look for? Many thanks