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Author Topic: IP Phones: Failover  (Read 2857 times)

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Offline jhand

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  • Location: Jax, FL
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IP Phones: Failover
« on: July 24, 2013, 06:57:12 PM »
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!

“The problems of the world cannot possibly be solved by skeptics or cynics whose horizons are limited by the obvious realities. We need men who can dream of things that never were." -JFK

Online MacGyver

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  • Location: Dallas, Texas
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Re: IP Phones: Failover
« Reply #1 on: July 24, 2013, 10:13:26 PM »
Great question.  I was thinking the later firmware versions had an option in the phone for a second address, but if so obviously not in your version which is all we care about so let's dig into it.

A few options come to mind that require hardware which range from modifications to the cabinet, to implementing routing tables in a Linux box or a dual wan router with failover out in a real datacenter somewhere.  That said though I think the easiest and most economical route would be to implement a Virtual IP failover type address.  As you can spin up an entire virtual server now for $9.95/month I would think simply leasing a VIP with failover would be very economical.  You would probably want to go somewhere other than one of the cheap banner ad guys though.  I'm thinking it's probably available through google, or certainly Amazon's hosting, but if not contact Rackspace.

If you want, I can close this thread and link a copy over to the networking forum.  Then some of the other network savy guys may chime in, but I think the VIP will offer you a low cost 4-9 solution.

Added:  I was told this company may also offer a VIP solution:
http://go.8x8.com/hosted-pbx?source=PS-Google-PBX&adgroup=Virtual&keyword=virtual%20phone%20number&gclid=CP7E8drYybgCFSdk7Aodu0AAIg
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Offline telemarv

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Re: IP Phones: Failover
« Reply #2 on: July 25, 2013, 07:11:18 AM »
What kind of phones are these? There are some brands/models which will take a primary and secondary IP address.
Marv CCNA


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