[e2e] Can feedback be generated more fast in ECN?

[Vijay Gill]

On Wed, 14 Feb 2001, David P. Reed wrote:


> You don't want to operate a network in a highly congested mode.  Router
> congestion should be rare, or your provisioning, your "admission control"
> (including such trivial things as restricting edge port capacities to
> reduce overcommitment of backbone capacity), or your closed-loop flow
> controls are not doing their job.

Restricting edge port capacities do not necessarily imply that there will
never be congestion in the core. See Mike O'Dells excellent email
(archived at: http://www.interesting-people.org/200011/0058.html) for more
details on this.

We've seen in some fairly large networks that in general, the physical
topology tends to lag the where the traffic wants to go by some number of
months to some weeks. This could of course be an result of a very short
planning horizion coupled with very long provisioning times, but thats
what the reality happens to be.

I am sure someone will come up with a counterexample of a network that
doesn't have these problems, but in my limited experience, that is what
happens more often than not. Also, I am simplifying by ignoring backhoe
fade, which is a short term (on the order of hours for the most part, the
china cable cut notwithstanding) issue.

/vijay