[e2e] Random losses on very high speed networks

Cannara cannara at attglobal.net
Tue Jul 22 19:15:41 PDT 2003


I don't believe anyone was whining Constantine.  It's simply that bandwidth is
the wrong word to use in English for data rate, capacity, etc.  It remains
wrong no matter who uses, or used it, and for how long.  In an engineering
sense it's a wrongful confusing element in communication with others, so in
one sense its misuse is bad sientific manners, especially for text read by
people new to the discipline. 

In fact, it clouds the scientific background of research that has gone on,
since before Shannon and Nyquist, into symbol transmission.  It's hard to
justify misuse of the term when explaining how much effort has gone into
optimal signal encoding over many decades, in particular the amazing efforts
by modem designers, including Hayes.  No technical discussion of how modem
designers plowed the fertile field of bandwidth to increase capacity over the
years would make sense if bandwidth equalled capacity.

Personally, I find it humorous to see how many folks who advertise themselves
as learned in the field use "bandwidth" so incorrectly and persistently --
almost as if it's PC, and they're afraid to rock anyone's boat from whom they
may need funding or some other support in the future. It's an intersting
social phenomenon to me, becuase it demonstrates how some folks will sacrifice
even scientific accuracy for personal comfort. In any case, my students don't
misuse the terms on homework & tests.  :]

Alex

Constantine Dovrolis wrote:
> 
> > > I agree with you that "bandwidth" is largely misused in the
> > > networking and CS community -- anyone who takes a networking class
> > > and still misuses bandwidth for capacity (at any layer) shoulda
> > > flunked.  :]
> >
> 
> Folks, frankly, it is way too late to whine about
> the use of the term "bandwidth" in the networking context. People
> have been using this term to refer to "capacity or throughput" (bps),
> as well as to "physical bandwidth" (Hz), for decades. I can
> recall the former use of the term in Jacobson's 88 paper, but I am
> sure that there are earlier references too.
> 
> Besides, the context in which the term is used is so different
> for Hz vs bps that probably it never causes confusion. And at the
> end of the day, the two "bandwidth" concepts are not totally
> irrelevant after all - see Shannon's law.
> 
> Constantinos
> 
> --------------------------------------------------------------
> Constantinos Dovrolis | 218 GCATT | 404-385-4205
> Assistant Professor | Networking and Telecommunications Group
> College of Computing | Georgia Institute of Technology
> dovrolis at cc.gatech.edu
> http://www.cc.gatech.edu/fac/Constantinos.Dovrolis/




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