WAN Failover

Hey all,

I was wondering if any of you guys could help me out with this one, because I’m at the end of my wits.

We are running Asterisk (who comes up with these numbers :smile:) and are using GrandStream (GXP 2000 and 2010) and Linksys SIP phones. We have a FortiGate 80C firewall with 2 WANs. The Asterisk PBX is hosted outside our LAN, so all phones connect to a public server via DNS name over the WAN.

WAN failover has been configured and works perfectly… as soon as one of the WAN links fails, all traffic is diverted to the other WAN link and users don’t even notice this (when browsing the net, etc).

The problem is that the phones don’t work, or rather; after a WAN failover, we can hear a caller speak but they can’t hear us. A reset of the phone solves the problem, but that’s not really what we want.

Could anybody point me in the right direction? What could be the problem here?

Thanks in advance!

Kind regards,