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Re: XAUI, SFF connectors




Hi Roy

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> Date: Mon, 24 Jul 2000 11:23:15 -0500
> To: rtaborek@xxxxxxxxxxxxx, HSSG <stds-802-3-hssg@xxxxxxxx>
> From: Roy Bynum <rabynum@xxxxxxxxxxxxxx>
> Subject: Re: XAUI, SFF connectors
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> 
> Rich,
> 
> What need does an interface card have for SFF connectors that can only put 
> one optical port within a 13 inch copper etch radius?  

It should be very reasonable to put two to four 10 Gig port on a PCI form 
factor card.

From what you and 
> others are making us believe, the form factor requirements for 10GbE are so 
> large that SFF connectors are a non-issue.  If 10GbE interfaces are going 
> to be so dense that we will need SFF connectors, why did we need XAUI?  I 
> can't see how you would need both.

XAUI provides high through put 3.125 Gb/s from two ASIC pin (+ few extra)
with very flexible interconnect, while keeping the package pin count
reasonable.  XAUI is the high bandwidth pipe to get data to and from 
your big ASIC.

The other reason for XAUI was to define an interface for the backplane
and ASIC so they can be developed, while everyone is arguing on the
right PMD for 10 gig.

Thanks,

Ali Ghiasi
Sun Microsystems

> 
> Thank you,
> Roy Bynum
> 
> At 10:13 PM 7/23/00 -0700, Rich Taborek wrote:
> 
> >Roy,
> >
> >As is usually the case, you always bring up interesting tangential
> >issues in your email. This time it's:
> >
> >"Given the form factor that would use XAUI, SFF connectors would not be
> >a requirement."
> >
> >What in the world does the XAUI interface, specified for use as an XGMII
> >extender, have to do with SFF connectors???
> >
> >Please enlighten me.
> >
> >Best Regards,
> >Rich
> >
> >--
> >
> >Roy Bynum wrote:
> > >
> > > Chris,
> > >
> > > I am not sure of your comment about LC having a proven track record for
> > > single mode implementations.  At present, WorldCom has not deployed any
> > > LC.  All of the connectors currently specified for SM installations is
> > > SC.  A particular vendor is attempting to get WorldCom to make use of 
their
> > > connectors.  ( I will not say how successful or not they are. )  Several
> > > system vendors are attempting to make use of LC, but at present, none have
> > > been certified.  Given the form factor that would use XAUI, SFF connectors
> > > would not be a requirement.
> > >
> > > Thank you,
> > > Roy Bynum
> > >
> > > At 04:28 PM 7/21/00 -0600, Chris Simoneaux wrote:
> > >
> > > >Our opinion is that LC is a better connector than MTRJ.  The LC does not
> > > >seem to suffer the possible damage that MTRJ can see with high 
mate/demate
> > > >cycles...due to the guide pin action.  Also, the LC has a proven track
> > > >record for singlemode whereas the MTRJ does not.
> > > >
> > > >PS: My feeling is the standards body's charter should be to specify a
> > > >connector. However, there's too much rhetoric in the procedure. Therefore
> > > >it's difficult to choose the best solution.  Inevitably the real winner/s
> > > >will come forward. Conclusion: Choose a connector at the standards 
> > level as
> > > >it can expose good points of each solution.
> > > >
> > > >Chris Simoneaux
> > > >Picolight
> >
> >-------------------------------------------------------
> >Richard Taborek Sr.                 Phone: 408-845-6102
> >Chief Technology Officer             Cell: 408-832-3957
> >nSerial Corporation                   Fax: 408-845-6114
> >2500-5 Augustine Dr.        mailto:rtaborek@xxxxxxxxxxx
> >Santa Clara, CA 95054            http://www.nSerial.com
>