How many ATA's at once?

Hi,

I want to know if there is a limit on the number of ATA adaptors one can
attach to a router - do they work on a port forwarding basis? if so surely
you can only attach 1?, I'm curious as there a routers with more than 1
interface - do these work differently internally ?

cheers for replies

JS

The Speedtouch 716g with a built in ATA has 2 ports

Me

On Fri, 19 Aug 2005 12:24:14 GMT, "Johnathan Smith" <polo@olo.com>
wrote:

>Hi,
>
>I want to know if there is a limit on the number of ATA adaptors one can
>attach to a router - do they work on a port forwarding basis? if so surely
>you can only attach 1?, I'm curious as there a routers with more than 1
>interface - do these work differently internally ?
>
>cheers for replies
>
>JS
>

Johnathan Smith wrote:
> Hi,
>
> I want to know if there is a limit on the number of ATA adaptors one can
> attach to a router - do they work on a port forwarding basis? if so surely
> you can only attach 1?, I'm curious as there a routers with more than 1
> interface - do these work differently internally ?
>
> cheers for replies
>
> JS
>
>

A port is different from an address - each IP address has 65535 ports.
Different applications will attach themselves to different ports, which
is how the computer knows where to send incoming packets.

In the case of a router, it knows that information coming in on port
5060 gets directed to port 5060 at the IP address of the ATA adaptor,
while something on port 5062 on the router would go to port 5062 at a
different IP address for another adaptor.

The ports don't even have to be the same because the router can change
them on the way through. You could have the router accept connections
for a web server on port 8080, then redirect them to the correct port 80
on the web server in your network.

Network Address Translation (NAT) is basically a clever way to put
several computers and devices on one IP address by changing the ports
involved.

Steve.

"Johnathan Smith" <polo@olo.com> wrote in message
news:ObkNe.92090$G8.38300@text.news.blueyonder.co. uk
> Hi,
>
> I want to know if there is a limit on the number of ATA
> adaptors one can attach to a router - do they work on a
> port forwarding basis? if so surely you can only attach
> 1?, I'm curious as there a routers with more than 1
> interface - do these work differently internally ?
> cheers for replies
>
> JS

I have a Fritz!Box Fon combined modem/router/ATA which has 2 phone ports.
I also have a Sipura SPA-2000 plugged into it with another two ports. It
all seems to work ok, but I haven't tried adding anything else..!

Ivor