On Sat, 12 Oct 2013, Michael Welzl wrote:
My question is, why is none of this happening?
My guess is that the rule to always deliver packets within a stream in order. If packets within the same stream have different DCSP values, there is a risk that they will go into different queues and they might be delivered out of order. A lot of applications that do real-time will have a PDV buffer, but won't have much of a out-of-order buffer. If a packet with sequence number 10 arrives after sequence number 8, packet number 9 is often assumed to be lost.
AQM is not widely deployed at all on the Internet as it is today, and a lot of devices will just have 4 different queues. Also as you say below, putting packets into different queues might mean they compete with other traffic and you might get packet loss due to that.
It would of course be of interest going forward to look into your proposal. AQM/Bufferbloat movement could perhaps benefit from this, but the current thinking is to make sure that all streams get equal access to the media with minimal influence between them, not that much to decide what packets within a stream to select for drop.
-- Mikael Abrahamsson email: swm...@swm.pp.se
