[asterisk-users] Multiple route failover zaps registration

[James Sharp]

On 12/12/2011 12:35 AM, Mike Diehl wrote:
> Actually, I've configured the phones to use DNS SRV records to find the Asterisk
> server, and this works very well.  The problem is that when the router fails
> over, the phones IP address changes and this causes them to be unavailable
> from Asterisk's point of view.
>

And that's why I was suggesting the short registration timer.  I'm 
assuming that the LAN connections/WRT54 is for client phones, not the 
server.

The phone registers, Asterisk sees it as coming from 75.0.0.1 port 5060 
(the external IP of the WRT54).  And the phone re-registers every 30 
seconds, and Asterisk just refreshes the registration.

Now, the primary internet connection falls over and the WRT switches to 
the other connection.  If you set the registration timeout to a short 
interval, the phone sends out a register message and Asterisk sees it as 
coming from 85.0.0.1, port 5060.  Asterisk then updates the registration 
IP for that peer and it can deliver and receive calls from those phones.

The only thing that will happen is that active calls *will* get dropped. 
  There is no way to hide the IP change from that without the VPN tunnel.