Baltimore train tunnels (was Re: Vulnerbilities of Interconnection)

Sun Sep 8 23:21:06 UTC 2002

At 09:47 PM 9/7/2002 -0400, Sean Donelan wrote:
>Unlike phone calls, TCP traffic doesn't occur in fixed bandwidth
>increments. TCP traffic, 90% of Internet traffic, is elastic. By design,
>TCP adjusts the traffic rate to keep the bottleneck congested.  As the
>bottleneck moves, traffic reacts by increasing or decreasing the rate to
>match the available capacity.  This feedback occurs independently of what
>is happening on nearby traffic paths.  Even if there is available
>capacity on elsewhere, the current Internet design is not very good at
>using it.  Some people view this as an inefficient use of available
>capacity, other people view it as a self-protective mechanism.

Thank Goodness for well-behaved applications, right? ( Misbehaving TCP 
stacks and UDP-based apps don't obey these back off rules. ) I remember Van 
Jacobson gave a presentation back in 1997 that spoke about the problems 
with applications that didn't exhibit these characteristics: 
http://www.academ.com/nanog/october1997/

It would be interesting to see some recent verification that well-behaved 
TCP-apps are the norm on the Internet...any data out there in this regard?

Bill