Does differentiating traffic into multiple timing classes make traffic timing analysis easier? (For example, while high-latency traffic is better protected from fingerprinting, low-latency traffic is easier to identify and fingerprint.)
The opposite should be the case, as the delaying of HL traffic should slightly obfuscate the traffic patterns of LL packets. The idea is to send everything through the mix but only delay what doesn't require performance with low latencies.
Nevertheless, we are not sure if it's more secure to let the user decide delays for packets (like in the alpha-mixing approach) to get a greater fraction of the overall traffic delayed or to assign random delays within the relay, based on a classification of the packets.
The latest stable release is Tor 0.2.7.6.
... and as there is also the new scheduler included we will continue our work with the latest version :)