[e2e] a new IRTF group on Transport Models
David P. Reed
dpreed at reed.com
Tue Jun 7 12:02:32 PDT 2005
Clark Gaylord wrote:
> as example: corruption could be cell loss. cell loss could be due to
Interesting... by blurring the concept of "cell congestion" together
with "router congestion" you end up with a confused description of the
TCP is based on a model where datagrams get through or they don't.
That's the IP model.
The engineering approach is to force all situations into those two
cases. Enhancing TCP or replacing it would be possible if the possible
outputs that result from a sequence of inputs could be characterized,
and doable if the characterization has some predictable structure.
If you try to design an end-to-end protocol where the inputs map to
arbitrary outputs (any causal output stream-generating process that can
be computed by a finite physical apparatus is as likely as any other), I
doubt you will succed.
This is ultimately why we put "cell-based links" into a modular black
box that doesn't try to expose the cell structure of a datagram to the
It's also why we normally use the "digital abstraction" instead of
modeling digital computers as analog machines. One could do
otherwise. One could even argue that it would be more "efficient" for
some meaning of the term efficiency.
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