Been totally happy with Zyxel, looked for 2 years before settling on it. I have the USG100, fantastic, does OSPF. I was using it with load balancing since I had 2 6 meg lines, now have one 6 and one 57 so changed it to route all to 57 unless that WAN is down or overloaded. FreeSWITCH goes out on both WAN and using SIP ALG failover is perfect. Check the web site, they just introduced faster models USG110, etc. You can get 3 or more WANs too. Config is object oriented so takes getting used to but then is really easy since duplication is eliminated. Been rock solid for 3 years now and plan to buy a new one. Great config options and documentation is first rate. Go to the web site and download the manual(s). Again, I spent 2 years looking and recommend these to anyone.
> I think this is the wrong place to ask this question, but what you need is a router that supports OSPF or BGP as routing protocols.  Set your main WAN link as a higher cost than the backup.  Once one of the links fail the other will automatically pick it up.
> You can get some Sonicwall or Cisco equipment for under 1K or if you want opensource get a buffalo router which has ddwrt or tomato which they both support this.
>> This is not a freeswitch question. I am sorry.
>> But looking for a Dual WAN router suggestion?
>> I try the pfSense and find a huge limitation, when WAN interface down. It keeps the firewall states and phones never able to connect through the second wan, unless someone clear the firewall rules manually.