[Bloat] Detecting bufferbloat from outside a node

[Toke Høiland-Jørgensen]

Neil Davies <neil.davies at pnsol.com> writes:

> I don't think that the E2E principle can manage the emerging
> performance hazards that are arising.

Well, probably not entirely (smart queueing certainly has a place). My
worry is, however, that going too far in the other direction will turn
into a Gordian knot of constraints, where anything that doesn't fit into
the preconceived traffic classes is impossible to do something useful
with.

Or, to put it another way, I'd like the network to have exactly as much
intelligence as is needed, but no more. And I'm not sure I trust my ISP
to make that tradeoff... :(

> We've seen this recently in practice: take a look at
> http://www.martingeddes.com/how-far-can-the-internet-scale/ - it is
> based on a real problem we'd encountered.

Well that, and the post linked to from it
(http://www.martingeddes.com/think-tank/the-future-of-the-internet-the-end-to-end-argument/),
is certainly quite the broadside against end-to-end principle. Colour me
intrigued.

> In someways this is just control theory 101 rearing its head... in
> another it is a large technical challenge for internet provision.

It's been bugging me for a while that most control theory analysis (of
AQMs in particular) seems to completely ignore transient behaviour and
jump straight to the steady state.

-Toke