The last couple of years, we've had two ISP's on premise. One (XS4ALL) for basic Internet Access via VDSL, and one our (VoIP) phone provided by Ziggo. The Ziggo phone services includes free (and ultra lite) Internet access through the use of their cable modem. It's ultra-lite, since it's only 256kbps. More than enough for VoIP, but not nearly enough for modern basic Internet access.

Having these two ISP's means that I should be able to provide some redundancy in case my primary DSL connection fails (for whatever reason). Preferably an automated fail-over of some kind.  Since there are no dynamic protocols available from either ISP (the Internet service is consumer-grade), I have to find some work-around.