Spectral Probing, Crosstalk and Frequency Multiplexing in Internet Paths

The authors present an end-to-end active probing methodology that creates frequency-domain signals in IP network paths. The signals are generated by periodic packet trains that cause short-lived queueing delay spikes. Different probers can be multiplexed in the frequency-domain on the same path. Further, a signal that is introduced by a "Prober" in one path can cause a crosstalk effect, inducing a signal of the same frequency into another path (the "Sampler") as long as the two paths share one or more bottleneck queues.