[asterisk-users] How to have Asterisk respond from the IP address used for registration

[Gordon Henderson]

On Thu, 27 May 2010, Mike wrote:

> That was a simplified example. I actually have two links from different
> ISPs, totally different networks.  Those on provider A should talk to
> provider`s A IP address and have their answers come back from provider's A
> IP, and those on provider B should talk to my provider B NIC and get the
> response back from that IP.
>
> This is all to make sure latency is kept to a minimum.  Provider A`s network
> doesn't peer to provider B, so latency is horrible when the customer doesn't
> use the right IP address.
>
> The reason why I am not using a diff server per provider is that for some
> customers, half the phone will be on provider A and half on provider B
> (home-based personnel).  They still keep hints and stuf to work as if they
> were on the same server.
>
> So my original question I believe is still valid, even if the IPs used as
> exemple made little common sense (as you`ve rightly noted)

This isn't really an Asterisk issue, it's network/routing - however ...

Two solutions I can think of. The first is the easiest is to get a 
separate router with three network interfaces - one goes to your LAN with 
the asterisk server, the other 2 to the 2 ISPs - the router then does all 
that's needed to keep the streams separate, or does load balancing, or 
whatever. There are many makes and some even run Linux.

The other way is to have 2 NICs on the Asterisk box, each connected to one 
of the 2 ISPs, then you need some routing magic on the Linux box to keep 
the streams separate - this example:

   http://lartc.org/howto/lartc.rpdb.multiple-links.html

builds a Linux router, but it should work with applications running on the 
router (which is jus a Linux box) itself.

Good luck!

Gordon