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RE: Equalization and benefits of Parallel Optics.

My interpretation would be a little different, i.e. an elaboration of the one that Chris DiMinico posted a few days ago (29 July):
At the time the multimode physical layer objectives were agreed to the intent was establish two distance targets for In-building cabling. And, to leave the MMF fiber type somewhat vague in order to allow for flexibility in PMD implementations. The usage of the word "installed" in the 100 meter objective was to identify the MMF with the MMF currently referenced in 802.3z. The omission of the word "installed" was to implicitly allow for the new higher bandwidth MMF fiber. This allowance would be based on careful evaluation of the PMD proposals to meet the distance objectives and cost considerations.
The following applies to the current implicit differences in the MMF distance objective and fiber types.
+++++Installed MMF, MMF as referenced in 802.3z.
+++++MMF, Either installed MMF or the Next Generation MMF fiber specifications currently proposed in both TIA and ISO or both.
In particular the phrasing above for "Installed MMF" means the MMF cabling specified in the  2 columns for MMF in Table 38-12 of 802.3 - 1998 Edition (BOTH FDDI fiber and 200 MHz*km 11801 fiber). The context for those specifications is set forth in clause 38.10. There is one phrase in 38.10 that I would say is not strictly correct. Where is says "The term channel is used here for consistency with generic cabling standards." I would correct that to say "The term channel is used here for consistency with generic premises cabling standards.".

I hope this helps clarify what we have on the table now.
Whether or not we should change it is a different discussion.


At 01:16 PM 8/3/00 -0700, Jonathan Thatcher wrote:


My interpretation is that "MMF" indeed means installed or new, as indicated.
This is clearly defendable.

Defining "installed MMF" to be the same as 802.3z fiber is still ambiguous.
It has two potential meanings:
1. All MMF fibers referenced in 802.3z will run to 100 meters.
2. At least one MMF fiber referenced in 802.3z will run to 100 meters.

My interpretation here is that "1." was intended, not "2." In short, that
"installed MMF" included an assumption that 100 meters would be achieved on
"160 MHz*km:, 62.5 micron (FDDI-grade) fiber.


>-----Original Message-----
>From: Rich Taborek [mailto:rtaborek@xxxxxxxxxxxxx]
>Sent: Wednesday, August 02, 2000 9:25 PM
>Subject: Re: Equalization and benefits of Parallel Optics.
>I believe that Chris Diminico did an excellent job of
>clarifying the two
>MMF objectives in his recent note to this reflector:
>tml. That
>note provides the following clarifications:
>Installed MMF - MMF as referenced in 802.3z
>MMF - Either installed MMF or the Next Generation MMF fiber
>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,
>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
>> >
>> >-----Original Message-----
>> >From: Roy Bynum [mailto:rabynum@xxxxxxxxxxxxxx]
>> >Sent: Wednesday, August 02, 2000 7:37 AM
>> >To: Paul Bottorff; Booth, Bradley; stds-802-3-hssg@xxxxxxxx
>> >Subject: RE: Equalization and benefits of Parallel Optics.
>> >
>> >
>> >
>> >Paul,
>> >
>> >As part of the distance Ad Hoc, I was under the impression
>that the 300m
>> >objective was for new technology MMF in the building
>risers.  The Ad Hoc
>> >was told that 100m over "installed" MMF was feasable at a
>symbol rate of
>> >over 10Gb, equivalent to the proposed 850nm serial PMD.  Were we
>> >mislead?  I don't know.  As a customer participating in
>this process and
>> >going back to looking at the most likely areas of initial
>> >and the implementation practices, I am the more serious
>about holding the
>> >people that said that they could do the serial 850nm PMD to
>their implied
>> >promise.
>> >
>> >Thank you,
>> >Roy Bynum
>> >
>> >
>> >At 01:33 PM 7/27/00 -0700, Paul Bottorff wrote:
>> >
>> > >Brad:
>> > >
>> > >I also understand our objectives in the same way. We don't have an
>> > >objective for 100 m computer room connections. It seems
>to me the 300 m
>> > >objective was written for computer rooms. The 300 m over
>MMF could be
>> > >applied to any fiber solution.
>> > >
>> > >Cheers,
>> > >
>> > >Paul
>Richard Taborek Sr.                 Phone: 408-845-6102      
>Chief Technology Officer             Cell: 408-832-3957
>nSerial Corporation                   Fax: 408-845-6114
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