sting is a TCP-based network measurement tool that measures
end-to-end network path characteristics. sting is unique because it can
estimate one-way properties, such as loss rate, through careful
manipulation and observation of TCP behavior. In addition,
using TCP allows sting to leverage the existing Internet infrastructure
-- any TCP server can be used as a de facto measurement service -- and
it avoids increasing problems with ICMP-based network measurement
(blocking, spoofing, rate limiting, etc).