The company I work for uses two ISPs. These connections come to a firewall appliance which also handles failover. Should one ISP drop, it automatically routes network traffic thru the backup ISP. On the external side, we use a third-party dynamic DNS service to dynamically route inbound email and web traffic to our servers, depending on which ISP happens to be available. The entire system works beautifully.
Enter our Intertel Internet Protocol Resource Card.
We have a group of contractors working out of state which VPN to our network to access our applications. They also have been setup with IP phones, programmed to the public IP address of our IPRC card. We setup a pass-thru in our firewall. The phones have POE injectors, they plug them in-line with their PC's ethernet cabling, and all is well.
Except when it isn't well, and the primary ISP goes down. Doesn't happen often, but it DOES happen.
ALL OTHER SYSTEMS failover. These phones do not, and right now it's because the phones require being manually programmed with the public IP address (ISP A) that points to the IPRC. We have a public IP address ready to go on ISP B which points to the IPRC, but switching the phones over requires the phones be manually reprogrammed by hand. Which takes time. Which means these guys are off the phone for however long it takes to reprogram the phones.
This is less than ideal.
I've been scratching my head on this one for months, trying to come up with a solution. The dynamic DNS server provider we use does not have anything that would fit our needs, because no DNS is involved. Just an IP address.
What I picture is an (external/third-party?) IP address which the IP phones are programmed to look for. This IP address automatically forwards traffic to one of our two ISP public addresses depending on availability. I don't know of any other way to accomplish this, and starting to think this type of setup is impossible.
Does anyone have experience with these phones and possibly have any suggestions? Thank you in advance!