[SR-Users] Forwarding to backup server

[Daniel Tryba]

On Sun, Jul 22, 2018 at 11:11:12AM +0200, Pali Roh??r wrote:
> Kamailio should try to send SIP messages directly to foreign SIP domains
> and when it fails (e.g. user not available or foreign SIP is not
> running), then forward message to that my SIP <--> XMPP gateway which
> will try to deliver it via XMPP.

There are more scenarios you need to keep in mind. A simple one is if
lookup() fails (not registered if you are running a registrar on this
instance) to just change the domain in the R-URI and relay it there:

if(!lookup("location"))
{
	$rd="xmpp.example.org";
	route(RELAY);
	exit;
}
 
You can use a similar approach in failure routes primed:
failure_route[MANAGE_FAILURE] {
	if (t_check_status("[456][0-9][0-9]"))
	{
		$rd="xmpp.example.org";
		route(RELAY);
		exit;
	}
}

Be sure to use a different failure route (or add some logic to the if to
avoid infinite loops).