I actually had this issue as well. Turns out it was a somewhat common issue with Westell DSL modem/routers. I'm not sure of the specifics but the fix was to change the channel of the frequency band from 6 to 11. This is worth a shot. It doesn't really make sense that I would have to do this, but it did work for me.
The Red Rings are a tool used by Best Buy to push their stupid warranty plan. Seriously like 5 people asked me about the plan on the way out and I didn't ask for any help picking out what box I wanted... Sad when you have to worry that much about the product when you dish out over $300.