[Asterisk-Users] Q about IAX (and IAXy)

[Eric Wieling aka ManxPower]

Nabeel Jafferali wrote:
> This is somewhat related to my other query on the list regarding NAT
> traversal.
> 
> I have heard many times that IAX is "NAT-transperant". I am unsure how
> it accomplishes this.
> 
> I do know that SIP works like this: your SIP device send a request to
> the SIP server (usually on port 5060) with whatever command. The SIP
> server respends to your device's "apparent" IP and port (this is decided
> depending on how that NAT is set up, STUN, etc.). The voice is then sent
> to the "apparent" RTP port on your device (deciding what that is, again,
> would depend on the NAT set up).

Actually, ASTERISK's NAT support deals with the "apparent IP address", 
but that's just how Asterisk does it.  It's not a standard.

See the following for SIP and NAT:
http://voip-itec.tamu.edu/files/reference/voip-nat.pdf
http://www.cs.columbia.edu/sip/drafts/Ther0005_SIP.pdf
http://www.vonmag.com/issue/2004/julaug/columns/isenberg.htm



-- 
I am seeking part or full time employment in the Greater Toronto Area, 
My preference is part time employment with some telecommuting, but all 
offers will be considered. Contact eric at fnords.org.