[asterisk-users] Same provider - IAX sounds bad, SIP sounds great

[Alejandro Imass]

On Tue, Feb 28, 2012 at 8:28 PM, Carlos Alvarez <carlos at televolve.com> wrote:
> On Tue, Feb 28, 2012 at 6:14 PM, Alejandro Imass <ait at p2ee.org> wrote:
>> Please expand as to how you set-up a SIP ATA behind a common home
>> router set-up, without port redirection and/or use of a SIP proxy
>> and/or STUN server? Unless the ATA has some sort of magic (e.g. VPN
>> support) it _cannot_ be done.
>
> Go buy a WRT-54G or nearly any consumer-class router and just plug in
> a SIP device.  Done.  It works.  We *never* work on customer routers
> and very rarely have to tell them to reconfigure their router at all.

What you are saying seems impossible and makes no sense unless the
router is assigning a public IP or is "SIP aware" and knows how to
read the routing data contained inside the SIP packets, and none of
the consumer routers are SIP aware AFAIK, especially not the WRT-54G.

The other option is that the SIP ATA has WAN and LAN ports and the SIP
device is being assigned a public IP.

SIP does not NAT by itself because it can't, because there is no
routing info, it's simply impossible.