Re: [ledbat] MIN_CWND, was: ECN/AQM, was: 2 week last call for draft-ietf-ledbat-congestion-06

[Arjuna Sathiaseelan <[e-mail]>]

Dear Lachlan - thanks for your reply..


> No.  This confuses "better" with "gives a higher throughput to this
> user".  The whole point of congestion control is to do what is good
> for the network rather than maximizing the flow's own throughput.
> Throwing away information that the network is currently congested is
> not a *better* response.

Ofcourse I agree with you - that was the whole point of CC..However we
still have the liberty to perform actions (for e.g. opening multiple
TCP connections, or stopping and starting a new connection when we
find the Internet is too slow in responding etc)..And they all seem to
be legitimate actions  although not good for the network..App
designers want better performance for their apps - so they end up
thinking of new ways of circumventing the law of the Internet CC..and
their actions sound legitimate within the realm. Bob and others have
been trying to say this for the past few years - that there is no real
notion of fairness in the Internet today and Matt Mathis (who came out
with the notion of TCP-friendliness) agrees with it now.

So my belief is that next generation TCP could have a more aggressive
approach providing incentive for app designers but at the same time
being more reactive to congestion. Coupled with mechanisms such as
ECN, CONEX etc they could be effective..

But when it comes to LEDBAT, we cannot take this approach. We need to
be more conservative..

Regards
Arjuna