Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!tut.cis.ohio-state.edu!ucbvax!decwrl!amdcad!ncpjmw
From: ncpjmw@amdcad.AMD.COM (Mike Wincn)
Newsgroups: comp.dcom.lans
Subject: Re: Starlan/Ethernet compatibility
Message-ID: <26164@amdcad.AMD.COM>
Date: 29 Jun 89 02:31:45 GMT
References: <2009@wasatch.utah.edu> <2230006@hprnd.HP.COM> <1989Jun22.155454.7396@utzoo.uucp> <26097@amdcad.AMD.COM> <1989Jun26.163706.1078@utzoo.uucp> <26135@amdcad.AMD.COM> <1989Jun27.165911.1613@utzoo.uucp>
Reply-To: ncpjmw@amdcad.UUCP (Mike Wincn)
Organization: Advanced Micro Devices
Lines: 72

In article <1989Jun27.165911.1613@utzoo.uucp> henry@utzoo.uucp (Henry Spencer) writes:
>In article <26135@amdcad.AMD.COM> ncpjmw@amdcad.UUCP (Mike Wincn) writes:
[...]
>>access method.  As long as there are going to be many players it makes 
>>perfect sense to me that they should all be compatible at some minimal level.
>
>Provided that we understand the tradeoffs involved and the technical
>alternatives.  It is not at all clear to me that there is enough real,
>live experience with the hardware to justify that.

Granted.  How can I make this more clear?  AT&T, DEC, HP, SynOptics, and many
others provided a small mountain of technical data on TwstPr Ethernet over
the course of draft standard development.  The data consisted of combinations
of theoretical analysis, computer simulation, and _measured performance_ on
_real hardware_ in _existing installations_.  In many cases measured 
performance was indistinguishable from simulation and/or theory.  In cases 
where there was an observable difference, further work concluded that some 
of those differences were not significant enough to warrant concern.  Where
concern was warranted, the draft was modified to reflect that concern.

I don't know how else I can convince you, other than by wheeling a lab setup
and 'scope cart into your office.

My understanding is that TwstPr Ethernet systems have been in use in various 
sites for at least a year, and the market has shown little, if any, sign of
reluctance to continue.  And I'm talking production quantities, not some
tweaky, onesey/twosey thing that some technician threw together in a lab 
one otherwise boring afternoon...

(And before you ask, go call AT&T, DEC, HP, SynOptics, etc., etc.)

>>... Does it make sense to you that we 
>>SHOULDN'T invoke a process that weeds out those schemes "...whose 
>>practicality is very unclear" ?
>
>I think such a process would be great, if it existed.  The current
>standards process does not consistently do this.  IEEE, to give them
>credit, often does okay.  That's not universally true of other standards
>bodies, unfortunately.

Go back and re-read my earlier comments.  No system is perfect, let the 
others catch up to reality.  In the meantime, no one isforced to buy anything.
My disagreement is with uninformed conclusions. 

[...]
>>>There is also no shortage of standards that are functional, but verifiably
>>>inferior in essentially every way to the previous de-facto standards.
>>
>>Okay, I'll bite... verify it.
>
>The lower layers of ISO networking, versus TCP/IP.

...so I'm told.  Re-read my earlier comments.  Maybe a message will start to
sink in.

>>>... we have enough -- indeed, too many -- of them already.  We would
>>>be better served by one or two *good* ones than by standardizing every
>>>variation anyone's marketing department can think of.
>>
>>...and there once were people who thought that the world was flat, and that
>>there was no need to consider any other possibility.  
>
>And surprise surprise, once the dust settled -- as the result of real-world
>experience, not theological pontification -- one and only one possibility
>turned out to be useful and correct.  Do *you* feel any need to consider
>the possibility that the world might be flat? :-)

If you really understood my points, you already know the answer.

Mike Wincn
ncpjmw@amdcad.AMD.COM
(408) 749-3156