[asterisk-users] Cisco 7971 behind NAT

[Luki]

Darryl,

OK, that could work but it makes the use of these phones behind
consumer routers rather impossible. How many of those will inspect and
transform SIP packets? Oh why does Cisco have to do things differently
from everyone else...

Luki

2009/11/16 Darryl Dunkin <ddunkin at netos.net>:
> You need to enable SIP transformations on the firewall, the packets will
> have to be dynamically re-written to handle multiple Cisco phones of
> these models. Be sure 'nat=no' is set in sip.conf for the phones as
> well, or Asterisk will reply to the incorrect ports (source instead of
> the mangled contact header).
>
> In this case, you'll need to compile in the SIP connection tracking/NAT
> bits in the kernel, they should be able to mangle the packets
> appropriately. I have never tested this, as all my deployments have
> hardware firewalls with SIP support built-in.