DSL Modem Trouble Shoot

This is one of my favorite PC Magazines and one interesting article came up on February 2006 issue that I never heard of before but it's one of those good ones.

The Problem:
DSL modem looses the internet connection for no apparent reason. The activity LED goes dark but the DSL indicator remains lit. And the telephone line at times you unable to get a dial tone. I am using the line filters that they recommend. What do you think the problem is?

Everyone would assume it's the DSL modem. But there is no dial tone. The only possible solution is change the DSL line filter that goes to the phone which either had short circuited or failed. But this did require a phone call to the ISP.