[Asterisk-Users] Re: [Asterisk-Users Canreinvite=[yes|no] explained (new subject)

[Mike Machado]

Based on my post yesterday, and the call trace I have, if Asterisk were
to make a decision a little differently when sending the the ReINVITEs
to phone B in your example (lets say Phone A is the one behind NAT)
media might work both directions. In the trace I posted, asterisk first
send a reinvite with the private IP of phone A, but then it sent a
second reinvite with the visible IP of phone A, which I think would have
made the call work in some NAT environments, but then it sent a *3rd*
reinvite to phone B, back to the private IP of phone A, breaking the
audio from phone B to phone A.

What I think happened was when phone A send the 200 OK for its reinvite,
Asterisk saw the SDP info from that packet and triggered the 3rd
reinvite to phone B, but since nat=1 was on, it should have ignored that
SDP, or at least sent the visible IP in the 3rd reinvite and not the
private IP.

In case you don't have it handy, the call trace I am referring to is
here:

http://www.cheapnet.net/~mike/asterisk_excel_with_reinvite.log

In this log, only the 192.x network is nat'd. 10.x and 172.x have
straight routing between them. 10.10.11.77 is the visible IP to
192.168.222.197 according to 10.x and 172.x.