Simple Bandwidth Scanner (called sbws) is a Tor bandwidth scanner that
produces bandwidth measurements files to be used by Directory
Authorities.

The scanner builds two hop circuits consisting of the relay being
measured and a fast exit. Over these circuits it measures RTT and
bandwidth.

WARNING: This software is intended to be run by researchers using a
test Tor network, such as chutney or shadow, or by the Tor bandwidth
authorities on the public Tor network. Please do not run this software
on the public Tor network unless you are one of the Tor bandwidth
authorities, to avoid creating unnecessary traffic.