[Taf]

My graph has lots of very regularly spaced yellow spikes on it! What is wrong with my connection?

Some broadband routers exhibit patterns of behaviour. This is often because ICMP is handled at a lower priority than other traffic, so if a router does some form of housekeeping at regular intervals you can see patterns not unlike the graph below:

http://www.thinkbroadband.com/faq/sections/bqm.html