Internet scale packet timing collection only works when the traffic is not messed with when routing through TOR. It's quite a headache when {proxy}.appspot.com is used, or technical documents are exclusively routed through GoogleCache, or even CoralCDN for that matter.
There's even users who configure BitTorrent to use TCP instead of UDP so that it's very difficult to write DPI rules to parse out the TOR traffic. Couple this with meek, VPNs and traffic shaping tools and it's quite bothersome for them.
There's even users who configure BitTorrent to use TCP instead of UDP so that it's very difficult to write DPI rules to parse out the TOR traffic. Couple this with meek, VPNs and traffic shaping tools and it's quite bothersome for them.