[Serusers] STUN and symmetric nat again

[Arek Bekiersz]

Use SER nathelper module and rtpproxy.
Use SIP ping from SER every few seconds (not too sparse, because NAT 
will close; but not too frequent either - use 8 seconds).
If your device is capable of it - use SIP ping and RTP/RTCP ping every 8 
seconds.

--
Regards,
Arek Bekiersz


Istvan De wrote:
> Hi!
> 
> I've read about the above topic in the arcives and now I've got the same
> problem.
> 
> User A is behind a symmetric NAT -> a new port is bound for every
> different
> (external ip, external port) pair.
> User B has a connection to the net without any NAT or firewall.
> 
> User A wants to have a SIP+RTP session with user B. How?
> 
> I guess basically what is needed is forming of a SIP
> message like "send the your reply to the same ip and
> same port from where you have received this" and user
> A can send this to user B.
> 
> For the RTP session, a pretty similar thing would be
> needed like, A says to B: "I send you the RTP stream
> on your x port, send your rtp stream back to the same
> ip and port from where you receive mine".
> 
> How to setup such a SIP packet?
> Or maybe there is a standard solution for this already?
> (STUN wont help in this case I guess, and TURN is not
> an option for me.)
> 
> I've read about "symmetric SIP + symmetric RTP" maybe
> that is the same as I've described above?