Hi guys!

I try to use OpenSER with NATed-users and now I have some problem.
No I'll try to explain it.

I have the following network scheme:

mySIP-phone_behind_NAT --> NAT --> OpenSER --> OtherProxy --> other_SIP_phone

mySIP-phone_behind_NAT have some knowledges about external NAT_ip so it successfully
registered on OpenSER using nathelper module and location table have new record looks like:

user@mydomain
Contact: user@NAT_ip:5060
Received: NAT_ip:NAT_port

Then mySIP-phone_behind_NAT send new INVITE with Contact=user@NAT_ip:5060
OpenSER fixup this Contact using

fix_nated_contact()

and send INVITE to OtherProxy
with Contact=user@NAT_ip:NAT_port;nat=yes

Then 200OK and ACK successfully traversed via OpenSER and dialog esteblished.

Then other_SIP_phone sends BYE request using R-URI learned from previous
INVITE Contact-header=ser@NAT_ip:NAT_port;nat=yes
OpenSER rewrite this R-URI to user@NAT_ip:NAT_port and send it using t_relay(). The packet goes to NAT_ip:NAT_port
but mySIP-phone_behind_NAT sends "404 Not found" because it does not know anything about user@NAT_ip:NAT_port --
it expected user@NAT_ip:5060 as sended in first INVITE.

So, my question is: is this my misconfiguration or incorrect logic understanding ?

I have some ideas how to fix this problem, for eaxample:
when I got INVITE from mySIP-phone_behind_NAT I must rewrite Contact to user@mydomain
(assuming that requests to mydomain goes to OpenSER always). Then if OpenSER got BYE from other_SIP_phone
it will lookup() and restore Contact and Received info. But I have problem again: If I rewrite R-URI to Contact and t_relay() it -- packet will be discarded by NAT because it does not anything about port 5060. If I rewrite R-URI using Received info I will get problem discribed early.

Feature request "Allow AVP in t_relay()" (published in Tracker) will solve this problem

Any suggestion?

--
CU,
Victor Gamov