Thumb On the Scale? Study Finds 5 of 7 Broadband Meters Inaccurate 114
stox writes "For the 64 percent of Americans whose internet service provider imposes a broadband cap, and for those lucky enough to have a meter, I have some bad news. The president of the firm who audits many of the country's broadband meters says that he can't certify the measurements produced by five out of seven of his clients' meters because they don't count your bits correctly
Re:are you suprised?? (Score:5, Informative)
Fast and wrong, or slow and correct. (Score:5, Informative)
Building an incorrect bandwidth meter is easy. Incorrect meters will calculate your bandwidth like ( 'MTU size' * 'number of packets' = usage), which will over estimate usage by a large margin (30% off is common), since a large number of packets are much smaller then MTU, DNS replies for example. It is 'somewhat' more accurate to take ('average packet size' * 'number of packets') per user, since different usage will come up with a different avg_pkt size. Counting each packets size and keeping track of it is the most accurate, but also the most resource intensive therefore the least likely to occur in bulk by the ISP.
Another place that can cause a significant skew in total bits is where bandwidth is monitored. Most ISPs count traffic before the restriction of your slow connection, therefore packet loss and re-transmits get counted against you (if the ISP uses no, or a bad queuing discipline this can end up being a significant amount of bandwidth). Monitoring how much was downloaded is best done on the CPE, such as the cable modem or dsl modem, but that would lead to firmware hacks and such to lie to the provider.
They're UNDER-reporting! (Score:5, Informative)
Re:We need broadband meter readers (Score:4, Informative)
I'm sure these meters make mistakes both ways right? Occasionally under counting.
From the article:
"They are wrong by missing numbers by one way or another - sometimes it's over reporting, but more frequently the error is under reporting," he said. Under reporting should be a relief to those facing overage charges or service termination for going over their meters, but if the meters aren't counting the data properly, it is still a problem.