El Thursday 12 June 2008 08:59:55 Pezhman Lali escribió:
Dear,
I find that stun and symmetric nat can not work together ,
but some big sip providers like sipgate or fwd, added stun settings to
their ata as default without, any question about customer's nat type.
where is the key ?
AFAIK a device doing STUN test discovers the type of its NAT and returns a
value to the application invoking it (the ATA).
If the ATA receives "Symmetric NAT" when doing he STUN test it cannot set
public IP:port in the SIP messages since the ANT type will make them not
working.
So, it's a device decission wherever to use STUN or not depending on the STUN
test result. For example Twinkle or Ekiga refuse to set the public IP:port
discovered via STUN test if the result of the test is "Symmetric NAT".
So if a device (an ATA for example) does STUN test and receives "Symmetric
NAT" it shouldn't apply STUN to send requests.
--
Iñaki Baz Castillo
ibc(a)in.ilimit.es