[OpenSIPS-Users] Receiving requests via registration TCP connection

[Iñaki Baz Castillo]

2008/10/14 Bogdan-Andrei Iancu <bogdan at voice-system.ro>:

>> Well, I tryed it for long time in OpenSer 1.2 and it never worked as
>> expected. Anyway that's a different question.
>>
>
> What did not worked? could you open a new thread on this?

As far as I remember, it did never mantain the REGISTER TCP connection
with the client open. Let me try it again.


> when registering from behind a NAT, opensips will learn the received IP and
> used this one (and not the contact) to deliver calls. So, if the TCP
> connection of the REGISTER is still one, it will be re-used (as the target
> is the same).

Imagine there is no NAT.
UA registers with the proxy by sending a REGISTER via TCP from random
port 12345 (but of course UA listens in 5060). The REGISTER Contact
says, of course:
  Contact: user at UA_PUBLIC_IP:5060;transport=tcp

Now imagine that the proxy, for whatever reason, forwards requests to
the UA using the previous TCP connection (still open), this is, with
destination port 12345.
Should the UA accept those requests?
Shouldn't the UA rejects them because they don't come via 5060 port?




>> Bogus? well, the RURI is correct since it's exactly the Contact sent
>> by the UA during registration, but the UA receives the request using
>> the random port used for the REGISTER instead of receiving the request
>> via the LISTENING port (5060).
>> This is the main question, is it valid per RFC 3261?
>>
>
> Not sure if the RFC3261 says something on this matter - it is more a logical
> one I would say.....Let me check, SIPit is the right place for this ;)

As Klaus said, RFC 3261 decides "NAT doesn't exist" XD


Thanks a lot.


-- 
Iñaki Baz Castillo
<ibc at aliax.net>