Hi!

Has anyone tested how does configuring SQM on Tor nodes influence the quality of circuits over the node? Throughput, latency? So given that circuits have 3 hops in serial I would assume that any buffering/latency issues on nodes combine in a bad way. So using some smart queue management (SQM) might improve things?

https://www.bufferbloat.net/projects/bloat/wiki/More_about_Bufferbloat/#why-...

So besides bandwidth measurements of nodes, should we also measure latency contributions by nodes? I think this is the whole idea behind the Bufferbloat movement, that it does not matter for user experience the final throughput if you have bad latency. That what most users perceive as "fast" is in fact good latency experience.

Tor have notions of sustained and burst bandwidth, but this to me looks like just simplified QoS configurations. Shouldn't a better configuration be "do not increase latency by more than X"? Then if you hit the bandwidth limit, you are obviously increasing the latency more because some packets are not getting through. But it also captures the behavior better than "bursting is allowed up to Y".

Mitar