Re: 3PMD Proposal
I have to agree with Larry's thoughts 'Arghhhh!!!'. I would opt to
scrap the 1300 nm wwdm solution if a patch cord is required.
Joel
------------------------
Larry Miller wrote:
>
>
> Arghhhh!!! Are we really back to that, David? The offset patchcord has
> been terribly unpopular with us, adding so much cost that it nearly
> doubles the cost of 1 Gb MM LX links.
>
> Is the Agilent 4X WWDM going to work with SMF? I will be wanting to
> know that.....
>
> Larry Miller
>
> -----Original Message-----
> From: david_cunningham@xxxxxxxxxxx
> [SMTP:david_cunningham@xxxxxxxxxxx]
> Sent: Monday, June 12, 2000 9:04 PM
> To: Bernd.Prediger@xxxxxxxxxxxx; piers_dawe@xxxxxxxxxxx
> Cc: Stds-802-3-Hssg@xxxxxxxx
> Subject: RE: 3PMD Proposal
>
> Bernd,
> the offset launch patchcord is assumed for the 1300 nm WWDM
> case for
> 10 Gigabit Ethernet. As was documented in IEEE 802.3z
> 1000BASE-LX the
> offset launch patchcord ensures a worst-case minimum bandwidth of
> 500
> MHz.km. For 1300 nm links the inclusion of the offset launch
> patchcord
> obsoleted the 385 Mhz.km modal bandwidth value that was present
> in some
> older drafts of the 1000BASE-LX clause.
>
> In conclusion, since the offset launch patchcord is part of the
> 1300 nm WWDM
> proposal 500 MHz.km is the correct modal bandwidth to use for the
> multimode
> links.
>
> Best wishes,
>
> David.
>
> -----Original Message-----
> From: Bernd.Prediger@xxxxxxxxxxxx
> [mailto:Bernd.Prediger@xxxxxxxxxxxx]
> Sent: Wednesday, June 07, 2000 9:49 AM
> To: piers_dawe@xxxxxxxxxxx
> Cc: Stds-802-3-Hssg@xxxxxxxx
> Subject: 3PMD Proposal
>
>
> Hello Piers,
> I just got through Del's presentation from Ottawa again and
> stumpled over
> your calculation for the "Minimum Range" of CWDM over installed
> MM-Fiber
> (Slide 4).
> You calculated 2-300m for all 500MHz*km fiber but I understood
> that since
> Gigabit Ethernet the worst case effective bandwidth everbody
> agreed on is
> 375MHz*km. Our calculation with the latter value let to about
> 180m.
> What am I missing here? (Of course we used your spreadsheet!)
> Best wishes
> Bernd
>
--
Joel Goergen
Force10 Networks
1440 McCarthy blvd
Milpitas, Ca, 95035
Email: joel@xxxxxxxxxxxxxxxxxxx
Direct: (408) 571-3694
Cell: (612) 670-5930
Fax: (408) 571-3550