Earlier quoted context omitted.
The ISP I work for does, and it's a very large one (not in the US). If a router is not ours, we check for sync or if PPPoE is up. We tell the customer what's the result of our tests and offer a technician if they are willing to pay in case it's not our fault. Most people are unwilling to pay, and yell at customer service. Most of the times, specially when the router has sync it's customer fault.
> we check for sync or if PPPoE is up. The problem with this kind of procedure is that it's only a reasonable way to locate the problem when there are problems at that very moment. You're getting stonewalled when - during the day - you're reporting that it frequently loses sync during the night.
You put a customer ID in the tracking system an it queries and stores results. It also performs analysis automatically, but most cases just puts the result in a frontend for analysis.