If your Internet access is down and you are not watching, is it really down? For most people the answer is most likely - who cares! Since our Internet connection had recently been down a few times, when I did notice it and I was getting curious about how frequently this was happening. Besides, it might be interesting to get a long term record on the stability and "quality" of our ISP and maybe even compare it with the results from users of competing ISPs. What does it mean for Internet access to be working? Is it enough to check that the link between our home router and the ISPs access router is up and working (a DOCSIS cable plant in my case). Or should we include end-end application layer scenarios like the ability to get my email or my files from some place "in the cloud"? But what exactly represents the "the cloud" or "the Internet"? In reality they are massively large distributed systems at a global scale, consisting of millions o