[Codel] [Bloat] Little's Law mea culpa, but not invalidating my main point

Toke Høiland-Jørgensen toke at toke.dk
Fri Jul 9 19:37:16 EDT 2021

"Holland, Jake via Bloat" <bloat at lists.bufferbloat.net> writes:

> Hi David,
> That’s an interesting point, and I think you’re right that packet
> arrival is poorly modeled as a Poisson process, because in practice
> packet transmissions are very rarely unrelated to other packet
> transmissions.
> But now you’ve got me wondering what the right approach is. Do you
> have any advice for how to improve this kind of modeling?

I actually tried my hand at finding something better for my master's
thesis and came across something called a Markov-Modulated Poisson
Process (MMPP/D/1 queue)[0]. It looked promising, but unfortunately I
failed to make it produce any useful predictions. Most likely this was
as much a result of my own failings as a queueing theorist as it was the
fault of the model (I was in way over my head by the time I got to that
model); so I figured I'd mention it here in case anyone more qualified
would have any opinion on it.

I did manage to get the Linux kernel to produce queueing behaviour that
resembled that of a standard M/M/1 queue (if you squint a bit); all you
have to do is to use a traffic generator that emits packets with the
distribution the model assumes... :)

The full thesis is still available[1] for the perusal of morbidly curious.


[0] https://www.sciencedirect.com/science/article/abs/pii/016653169390035S
[1] https://rucforsk.ruc.dk/ws/files/57613884/thesis-final.pdf

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