I was wondering if anyone could give me some advice on the usefulness of measuring the current load on a router. I have read the bandwidth authority specification, and I have a rough idea on how bandwidth authorities send a file and measure the current bandwidth experienced from the router. I was wondering would it be reasonable to utilize some sort of a packet pair technique to measure the available bandwidth on a Tor relay (or the current CPU utilization) ? Would it be less or more useful than what directory authorities already publish in the consensus? And if the relative usefulness is not known would this be an interesting thing to attempt? Does the way that current directory authorities measure has some limitations could be worked upon?
I have read some papers that do active probing or similar but those seem to be written before the bandwidth measurement by bwauths were introduced or else introduce a lot of traffic in the network. Are there any research papers anyone can point me towards that particularly talk about the limitations of the current measuring structure? Or give any opinions. Basically, my main question is whether it would be worth it to measure a router's load at any given point, and what sort of ways (if known) may be available. I do not intend to measure the entire set of Tor's router population but maybe just about a dozen (so that might not overwhelm the network). Any advice would be appreciated.