[Asterisk-Users] NATted phones transferring calls - BUG0003710

[Douglas Garstang]

> -----Original Message-----
> From: Alexander Lopez [mailto:Alex.Lopez at OpSys.com]
> Sent: Tuesday, March 28, 2006 9:04 AM
> To: Asterisk Users Mailing List - Non-Commercial Discussion
> Subject: RE: [Asterisk-Users] NATted phones transferring calls -
> BUG0003710
> 
> 
> I wont go into the details of NATs and how they work, they are beyond
> the scope of this fourum,even though it is important that we 
> understand
> NATs and their function as it pertains to Asterisk.
> 
> If Asterisk is not in the media path and it CANNOT transfer 
> the call if
> it is NATed. If you have canreinvite=yes, then the phone will 
> set up the
> media path between them. If you are not using NAT then asterisk can
> redirect the call, but if you are using NAT in cannot.
Asterisk IS in the media path.

> 
> NAT + (canreinvite=yes) = Media path direct to the phones, transfers
> will not work.
> !NAT + (canreinvite=yes) = Media path direct to both phones, but since
> phones are on routable networks phones can transfer.
Not doing that.

> 
> NAT + (canreinvite=no) = Asterisk stays in the media path so transfers
> and all functions will work.
> !NAT + (canreinvite=no) = Asterisk stays in the media path so 
> transfers
> and all functions will work, but will NOT allow use of NATed Devices.
We have nat=rfc3581 against the user and canreinvite=no. Asterisk is in the call path, so by your definition this should work. It does not. If we remove NAT, it does work. It is therefore somehow related to NAT. I've seen at least one other person report this problem.