Internet connectivity

My son said that it seems to him that our home internet connection drops out every half an hour or so. Perhaps he's right, perhaps he just gets impatient every half an hour. Time for some research.

First of all, one of the problems is that the cable modem is connected to a wireless router so if there is a problem, is it the modem or the router?

Whoa there! Step back. Firstly, do we have an intermittent dropout? Here's what I did first. My desktop box uses Linux (Fedora Core 11, to be exact. I have tried to update to 12 and 13 but both barf on me so I'm sticking with 11.) I create a shell script thus:

#!/bin/sh
while(true); do sleep 5 ; ping -c 1 www.google.com >> plog ; done &
while(true); do sleep 5 ; ping -c 1 www.bbc.co.uk >> plog ; done &
while(true); do sleep 60 ; date >> plog ; done &

then I let it rip and examine the (p)log file later. Indeed, the internet connection is lost on a regular half hourly basis. So, next question, is it my ISP (Virgin Media, so I'm inclined to jump to conclusions here!), or does my wireless router go to sleep every half hour? Time to put the thinking cap on. Tune in for the next exciting episode of Internet Repair Man....