[asterisk-users] Asterisk behind Multi-NAT question

[Anselm Martin Hoffmeister]

Am Dienstag, den 09.10.2007, 19:50 +0100 schrieb WipeOut:
> Hi,
> 
> Ok.. I know dual NAT is a problem for SIP..
> ie. UA - NAT - Internet - NAT - Asterisk
> 
> What about Multi-NAT where a dedicated public IP is mapped to the 
> private IP of the asterisk box..
> ie UA - NAT - Internet - Multi-NAT - Asterisk
> 
> http://www.draytek.co.uk/support/kb_vigor_multinat.html
> 
> Anyone tried it?

My experience with SIP, Asterisk and more than one NAT in the path is
not a good one. For example, several of my SIP hardphones refused to
work behind a dual-NAT

Phone (10.10.0.201) - NAT - internal net (192.168.174.0/24) - NAT -
Internet - Asterisk

where everything else worked as usual. Admittedly multiple NATs are not
necessarily a good idea to have, but that was a customer's network, not
mine ;-)

Also quite regular setups like

Phone - NAT - Internet - NAT - Asterisk

and

2 Phones - NAT - Internet - Asterisk without NAT
(One of those phones calling the other).

might work - or just be a source of trouble. This also seems to depend
on the cooperation of the NAT device; some work better than others.

IAX seems to handle NAT issues much better, in my experience, but I did
never have an IAX hardphone.

BR
Anselm