Connect 2 modems to 2 routers to 1 switch.

[steadyaero]

I work at a CPA office where we use VoIP via vonage and our cable ISP is Suddenlink. Our current setup uses 2 modems connected to 1 router (that has 2 WAN ports) connected to 1 switch. The phones draw from one modem and the computers draw from the other. However, someone recommended getting a second router. So the new desired setup is to connect the 1st modem to the first router and the 2nd modem to the second router and connect both routers to the same switch. What kind of router configuration is necessary? Thanks in advance!

Models for reference:
The old modems: Motorola SB5101N
The new modems: Motorola ARRIS SB6121
The current router: Cisco RV042
The new router: Netgear WNR3500L V2
The switch: Cisco SG 100-16
Phones: Linksys IP Phone SPA942 & Linksys IP Phone SPA962

Link to picture of drawing of our current setup: https://www.dropbox.com/s/e36hag9x7tqyflx/wiring%20diagram.pdf?dl=0
Link to picture of actual hardware: https://www.dropbox.com/s/qmp677wtsbzv8mp/20140919_142254.jpg?dl=0

 

[freshbakd]

What it the goal here? Are you trying to open more phones or add a pc or two? Does everything work?

 

[steadyaero]

What it the goal here? Are you trying to open more phones or add a pc or two? Does everything work?

Everything works for the most part. However, we are in a rural location that has low bandwith (3mbps down, 0.5 mbps up). And our phones go offline periodically, even in the middle of calls.

 

[dgingeri]

That probably wouldn't work so well. It would create a loop in the internet and probably cause one or both of your modems to be cut off by your ISP.

You'd need to get a router and switch that can be programmed for redundancy, that would talk to each other and detect when the other one went down, they plug both routers into both modems. (The method used to hook them up would be dependent on what routers you use.) These would be commercial grade, so they'll be expensive. I advise contacting a IT routing and networking consulting company for specific configuration and setup. It's a complicated process, and not something to be done by those without training.

It'll cost, but you have to weigh the business and cost/benefit analysis of losing your internet connectivity vs setting up the redundancy.

 

[bill001g]

Your current configuration with a single router running 2 wan connections is your best design. That router can then select which path to use.

If you use 2 routers you then must move all this logic back into the end users devices....a phone is pretty stupid.

It is not really possible to combine the 2 connection because they have different IP addresses.

 

[steadyaero]

Your current configuration with a single router running 2 wan connections is your best design. That router can then select which path to use.

If you use 2 routers you then must move all this logic back into the end users devices....a phone is pretty stupid.

It is not really possible to combine the 2 connection because they have different IP addresses.

What about adding a second switch?

 

[bill001g]

You could I suppose and then connect the different devices to the different switches but it really doesn't buy you much. You can do the same thing with a single switch if you work at it.

There really is no advantage to having 2 routers. The dual wan router is likely more than powerful enough to run both internet connection at full speed.