[Serusers] Forwarding to port 5060 when UA behind NAT

[Arek Bekiersz]

Dear list,


I have situation where SIP UA is behind NAT, that maps everything to
ports above number 61000. I use nathelper, rtpproxy and SER 0.8.12. 
Everything works fine.

Until I have UA that does not send "Contact" field in BYE (or OK for
BYE) during call termination. In this case SER is forwarding responses
not to NAT-ed port, but to port 5060.


QUESTION: What can be done to correct this situation?
Is this improved in new SER releases?

Sequence is as follows:


IP_of_A:61001 -> IP_of_proxy:5060
BYE sip:B at IP_of_proxy
loose_route
...


IP_of_proxy:5060 -> IP_of_B:5060
BYE sip:B at IP_of_B
...


IP_of_B:5060 -> IP_of_proxy:5060
SIP/2.0 200 OK
...


IP_of_proxy:5060 -> IP_of_A:5060   <WRONG! Should be 61001>
SIP/2.0 200 OK
...


It does not happen when terminating UA sends "Contact" field in first BYE.




-- 
Regards,
Arek Bekiersz