What Digi products could do this?

This is my application:
We have a reservoir where serial based controllers are located, at present we communicate with them via leased line with modems. At this site we installed internet public service for video monitoring of our installations.
People ask how we can use this ISP as backup line in case of a leased line failure.
What Digi products could do the job?

This is a question you would want to discuss with our sales department. The product that you will most likely be looking at will be the ConnectPort WAN VPN product, which can be used as a failover backup to leased lines. The number to reach our sales department is 877-912-3444, option 2.