Re: Optical Connectors
Geoff,
The VF-45 commonly known within SDOs as SG has been
standardized by the Fibre Channel, ATM Forum, ISO/IEC 86B,
TIA and referenced in the Token Ring. It's also indirectly
referenced as SFF through the RJ-45 footprint and IEC 86B
standard compliance by
the ISO/IEC 11801.
Cheers,
Tad
3M Telecom Systems Division
512-984-3847
P.S. Apology accepted
----- Original Message -----
Sent: Friday, July 28, 2000 1:50 PM
Subject: Re: Optical Connectors
> Tad-
>
> The discussion has gone
far afield of the traditional bounds for standards
> based
discussions.
> I know that you feel duty bound to protect your
product.
> To that end, and to also support my purposes, can we please
haul the
> discussion back to:
>
* Specifications for any
particular connector that are actually
> included in a standard adopted
by by a national or international SDO.
>
* Specifications (detail or
overall) that have actually been put
> on the table and have not yet been
rejected by a considering committee of
> an SDO.
>
> If your
attached message already meets these criteria then I apologize and
>
would ask that you still point these things out in standards based
terms.
>
> Thank you.
>
> Geoff
>
> At
10:57 AM 7/28/00 -0500, mailserv.mmm.com wrote:
>
>
>Rohit,
> >
> >There is a very fine line between technical
discussion and a marketing
> >pitch. Following yours <Please let me
know if anything is amiss. Let's try
> >and maintain objectivity
here> I feel obligated to reply to your note as it
> >misleads those
that are not experts in this field.
> >
> >First of all set of
numbers associated with each connector you've presented
> >is very
misleading. As you know there is a big difference between the mean
>
>and the maximum insertion or reflection loss values or between multi
mode
> >and singlemode fiber. Please be specific next time
around.
> >
> >Second, for your and other reflector
subscribers information the VF-45
> >singlemode insertion loss mean
value as published more than a year ago in a
> >technical report,
available upon request, is 0.19 dB with back reflection of
> >negative
56 dB.
> >
> >Third, the 4.9 fiber pitch of VF-45 reflects the
active devices can size not
> >the ability of the VF-45 ferrule-less
connector technology or active devices
> >to space the fibers and/or
active devices at larger pitch or as close as 250
> >micrometers
apart.
> >
> >Forth, I don't know if you're referring to the
cable or fiber so let me
> >elaborate on both. The duplex cables are
manufactured in both so-called
> >zip-cord and round structures. While
zip-cord is used typically for the
> >jumpers due to ease of
termination and ability to recover failed termination
> >of the single
ferrule connectors such ST, SC or LC the round is used in the
>
>typical cabling environment. The VF-45 represents an innovative,
>
>ferrule-less, plug and socket design in a RJ-45 format. The in-field
>
>installable socket can be terminated onto any cable design while jumper
is
> >provided as factory made product in a similar to UTP
fashion.
> >
> >If you're making references to fiber I advise
you to check L.K. Baker, G.S.
> >Glaeseman, Corning's fiber reliability
experts, paper titled "A mechanical
> >reliability study of bare fibers
under stress" presented September '99 at
> >the IICIT conference. To
make the long story short here are Corning's
> >conclusions for VF-45
wall socket:
> >
> >" The results show that wall socket
terminated with silica fiber have a very
> >low failure probability of
0.04% over 20 years. This corresponds to a 2.5
> >FIT (failures per
billion hours), which means that over 20 years
> >approximately one
wall socket would fail for every 1,000 installed.
> >
> >and
VF-45 plug:
> >"The results show that for the jumpers manufactured with
either standard
> >silica glass or a high durability fiber with the
proof test operation the
> >predicted failure rate falls to zero over
the 20 years service life"
> >
> >And one more thing in case
you don't know. All this for one-seventh the cost
> >of the traditional
ferrule-like connector design.
> >
> >
>
>Cheers,
> >
> >
> >----- Original Message
-----
> >From: <mittalr@xxxxxxxxxx>
> >To: Roy
Bynum <rabynum@xxxxxxxxxxxxxx>
>
>Cc: <stds-802-3-hssg@xxxxxxxx>
>
>Sent: Thursday, July 27, 2000 7:17 PM
> >Subject: RE: Optical
Connectors
> >
> >
> > >
> > >
>
> > Roy, I do not believe your assesment is correct. I can give you name
of at
> > > least 6 other BIG companies who are doing LC. That is
more than you can
> > > count for MT-RJ, I'm sure.
> >
>
> > > I think it will be instructive to give people a feel of
the various pros
> >and
> > > cons of various small form
factor devices. Please let me know if anything
> >is
> > >
amiss. Lets try and mantain objectivity here.
> > >
> >
> LC
> > > ---
> > > Fiber pitch: 6.25mm (simple and
easy to manufacture)
> > > Insertion loss 0.1-0.15dbm
> >
> Return loss: 50-60dbm
> > >
> > > Mu
> >
> ---
> > > Very similar to LC
> > > Only difference
is lack of latch which might be
> >advantageous/disadvantageous
>
> > depending upon whom you talk to
> > >
> > >
MT-RJ
> > > -----
> > > Fiber pitch: 0.75mm(difficult to
manufacture)
> > > Insertion loss 0.15-0.2 dbm
> > >
Return loss: ~40dbm
> > >
> > > VF (volition)
>
> > ----
> > > Fiber pitch: 4.9mm(special cabling
reqd.)
> > > Insertion loss 0.5dbm
> > > Return loss:
~20dbm
> > >
> > > Thanks
> > >
Rohit
> > >
> > > ps: I agree with a lot of people on
this reflector that it doesn't make
> > > sense to get into these
discussions on and on. Everyone has their own
> > > favourite
connector and the protocol is anyway independent of whether you
> >
> use SC or LC or MT-RJ.
> > >
> > >
> >
>
> > >
> > >
> > >
> >
>
> > >
> > >
> > >
_______________________________________________________
> > > Say
Bye to Slow Internet!
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>
> >
> > >
>
>