Testing Internet Speeds and Capacity
xaixili at live.com
Mon Nov 23 23:02:08 CST 2009
As mentioned, there is a limitation to TCP-based speed tests - TCP throughput is very sensitive to packet losses, particularly during slow-start, in addition to requiring end-host tuning (as an exercise, try running speedtest.net on a high bandwidth connection). You could use something called "available bandwidth", which is kind of like the "leftover capacity" on your path - I've been using this tool called pathload2: http://www.measurementlab.net/measurement-lab-tools#pathload2
Keep your friends updated—even when you’re not signed in.
More information about the NANOG