Extreme congestion (was Re: inter-domain link recovery)

Fred Baker fred at cisco.com
Thu Aug 16 06:46:12 UTC 2007

On Aug 15, 2007, at 10:13 PM, Adrian Chadd wrote:
> Well, emprically (on multi-megabit customer-facing links) it takes  
> effect immediately and results in congestion being "avoided" (for  
> values of avoided.) You don't hit a "hm, this is fine" and "hm,  
> this is congested"; you actually notice a much smoother performance  
> degredation right up to 95% constant link use.

yes, theory says the same thing. It's really convenient when theory  
and practice happen to agree :-)

There is also a pretty good paper by Sue Moon et al in INFOCOMM 2004  
that looks at the Sprint network (they had special access) and looks  
at variation in delay pop-2-pop at a microsecond granularity and  
finds some fairly interesting behavior long before that.

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