Randy,

So who actually measures their network performance and how?

We use a traffic flow monitoring system from Kaspia Systems. (www.kaspia.com) The Kaspia product collects all sorts of data from router ports and RMON probes, stores the data and performs various trend analysis. We collect traffic flow, router CPU usage and router memory information plus various errors. There is a data reduction process which runs once a day, and a very nifty web interface. The product isn't cheap, but the system definitely fills a void here. Maybe I should organize a talk on what we're doing with it for an upcoming NANOG? As an old instrumentation engineer, I think the basis of our use of the tool is pretty solid. Plus, I actually developed a means for calibration of the accuracy of the flow data. Haven't had time yet to work out a validation for the trends, but I'll get to it one of these decades. Also, the Kaspia people will give you a thirty day trial on their product at no charge. Regards, Bill McCauley