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Re: Equalization and benefits of Parallel Optics.




Roy,

It should be clear that the 300 MMF objective may be met by PMD
solutions which support this distance over either installed MMF or the
Next Generation MMF. That is the point of Chris DiMinico's
clarification. If one of the PMD solutions combined with NG MMG offers a
significantly more cost effective link cost solution at 300 m than any
other PMD solution over either installed or NG MMF, then I would say
that it is a good candidate for satisfying the "300 m over MMF".

It is the tradition of Ethernet to offer cost effective PHY solutions of
100 m, >100 m and <100 m. Therefore, both the current MMF/distance and a
potential new short haul MMF/distance objective are as traditional as
"Fiddler on the Roof".

Best Regards,
Rich
  
--

Roy Bynum wrote:
> 
> Rich,
> 
> You are entirely correct bout the issue of 75% to make any changes at this
> late date.  And I am in no way taking issue with what Chris Diminico
> said.  What I was hoping to express was the concept that the 300m objective
> as I understood it never specifically included "installed" or "legacy"
> fiber.  From what I understood, the only distance objective that
> specifically included "installed" or "legacy" fiber was the 100m
> objective.  The reason that the 100m distance was at 100m was because of
> the "tradition" of 802.3.  The ISO cabling specifications referenced by
> 802.3z and in the York motion were based on the original technical
> limitations of copper based 10mb Ethernet, not fiber base Ethernet.  As
> Geoff Thompson just stated in
> http://www.ieee802.org/3/10G_study/email/msg03199.html, if we are no longer
> bound by the tradition of "100m" because the technology does not apply,
> then we are able to define other specifications that are more appropriate
> to the technology and the market.
> 
> As an executive from a large network service provider recently stated to me
> in reference to the applications of the new Ethernet technology, "We are
> not in Kansas any more".  The traditional, comfortable, ways of at looking
> at the way Ethernet is deployed can be a handicap.  By re-evaluating how
> Ethernet CAN be deployed based on customer requirements and technology
> possibilities, P802.3ae can become even more THE "global" data link level
> protocol.  One of the basic distinctions is that the TF needs to be
> listening to the customers and asking the customers what they need instead
> of continuing to try to tell the customer what they are going to get.  If
> the TF fails to do that, then IEEE will lose control of the Ethernet
> standard.  This has already partially happened at ITU SG7 and in the case
> of "jumbo frames".
> 
> Thank you,
> Roy Bynum
> 
> At 09:25 PM 8/2/00 -0700, Rich Taborek wrote:
> 
> >Roy,
> >
> >I believe that Chris Diminico did an excellent job of clarifying the two
> >MMF objectives in his recent note to this reflector:
> >http://grouper.ieee.org/groups/802/3/10G_study/email/msg03164.html. That
> >note provides the following clarifications:
> >
> >Installed MMF  MMF as referenced in 802.3z
> >
> >MMF  Either installed MMF or the Next Generation MMF fiber
> >specifications
> >
> >There have been no objections to Chris's clarification. I fully support
> >these clarifications. I don't understand the purpose of any discussion
> >regarding exactly "how" the objectives were worded the way they are. The
> >fact is that the wording stands unless a change is agree to by 75% of
> >802.3 voters.
> >
> >Any objections?
> >
> >Best Regards,
> >Rich
> >
> >--
> >
> >Roy Bynum wrote:
> > >
> > > Chris,
> > >
> > > In the discussions about what could be achieved and what the various known
> > > applications were, based on the traditional use of Ethernet, the question
> > > was raise about whether MMF could support 10GbE.  There was even the
> > > question of installed fiber and the issue of older "gofer bait" MMF
> > > fiber.  I could be wrong, but my perception is that one of the fiber
> > > company people stated that the older MMF should be able to support 10Gb for
> > > the lateral 100m traditional lengths, and the traditional riser or 300m
> > > could be supported by the newer MMF.  The word "installed" was inserted in
> > > the motion proposal only, it was not agreed on by the people of the Ad Hoc.
> > > At the time that the 300m motion that included the word "installed" was put
> > > before the group, I remember thinking that this was not what was agreed on
> > > by the distance Ad Hoc, and of course it was very quickly corrected.  What
> > > was left ambiguous was that the words "new multi-mode fiber" was trimmed to
> > > be only "multi-mode fiber".  At least that is the way that I remember it.
> > >
> > > Thank you,
> > > Roy Bynum
> > >
> > > At 11:09 AM 8/2/00 -0600, Chris Simoneaux wrote:
> > >
> > > >Roy,
> > > >I would curious to know who made/implied promises of 850nm serial
> > > >implementation @ 10Gbps over 100m of installed fiber.
> > > >
> > > >My understanding (and I wasn't part of the meetings when the
> > objectives were
> > > >developed, so correct me if I'm wrong) was that there was little or no
> > > >representation from the 850 serial PMD guys.
> > > >
> > > >Regards,
> > > >Chris
                                    
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