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RE: [EFM] Changes to 100BASE-X and 1000BASE-X PCS, 10G RS

Forwarded from Piers Dawe.

Subject: RE: [EFM] Changes to 100BASE-X and 1000BASE-X PCS, 10G RS
Date: Tue, 2 Mar 2004 15:07:10 -0000
From: <>
To: <>, <>,

This is not JUST a project for the access network and that is not the
"whole reason they exist".  100BASE-LX10 and 1000BASE-LX10 like PHYs
existed before EFM, and we should be standardizing them right.  We have
known all along that they have general applicability.  Remember, 100
Mb/s on SMF started as a separate call for interest and was rolled into
EFM for synergy.

The EFM "environment" is not so different.  It's the same frames, same
rates, same wavelength, same fiber type as "legacy" 1000BASE-LX and
10GBASE-L.  Same optional OAM proposed for all.  Interoperable and
interchangeable PMDs. So why would the PCS be different?

I don't believe that the proposed mandatory PHY changes are
"particularly tuned" even for the access market and I don't see your
"less applicable - more applicable" trade off.   By demanding currently
non-standard behavior they go against Broad Market Potential,
Compatibility and Economic Feasibility even for the access market.  They
make it harder to connect a "legacy Ethernet" data backbone network to a
not-quite-Ethernet "EFM" access network.  Do NEMs have to make boxes
where some long wavelength GBIC ports have one PCS behavior and other
long wavelength GBIC ports have the opposite behavior?  I suppose a
service provider can go to ATM and back to join the two!

Let's quote from the 100BASE-FX over dual Single Mode Fibre Call For
Interest of two years ago.  Remember, as the web site says,
The 100BASE-FX over dual Single Mode Fibre Call For Interest resulted in
additional work being added to IEEE P802.3ah Ethernet in the First Mile
task Force.

 >From EFM minutes
Additional Objective: p2p 100Mb/s on SM fiber
Bruce T. presented a motion:
   To add an objective to the family of physical layer specifications
     100Base-X >3D 10 km over SM fiber
ALL - for 105; Against 4; Abstained 22
802.3voters - for 59; Against 3; Abstained 9
Motion passed

And from 802.3 minutes
<> :
802.3ah motion #1
   Add an objective to the family of physical layer specifications:
   100BASE-X >3D 10 km over SM Fiber
   All Y:105 N: 4 A:22
   .3 Y:59 N: 3 A: 9
   Motion Passed

And these quotations below (my emphasis) are from the20
100 Mb/s over Dual SM Fiber 100 Mb/s over Dual SM Fiber
Proposed PAR & 5 Criteria Proposed PAR & 5 Criteria

- Make amendment to Clause 26, 100BASE-FX, to include a 100Mbps dual SMF

Broad Market Potential Broad Market Potential
100BASE-X SMF is main candidate for volume applications in:
- Residential (FTTH)
- Commercial (SME, Shopping malls, etc.)
- Industrial (  <>
o Rapid growth anticipated in emerging areas
- fiber to the radio base stations (FTTR)
- fiber to WLAN HotSpots (FTTW)
- fiber links connecting office desktops (FTTD)


100BASE-X PCS & PMA assumed, and the 802.3 MAC
- No changes whatsoever to the MAC
- PHY identical to current 100Mbps Std except for a new PMD
- No change to Clause 24
- Retain all state machines, 4B/5B coding etc. of 100BASE-X
o Only need to extend Clause 26, 100BASE-FX PMD, to include SMF
o Physical medium compatibility through SMF
- Compatible with existing 1000BASE-LX
- Provides upgrade paths to higher speeds and multiple wavelengths, with
fiber plant untouched

- 100Mbps optical SMF components exist
- 'Pre-standard' links and systems already in commercial operation

100Mbps and EFM
o EFM deals with major additions to the 802.3 Std
o 100BASE-X dual SMF only requires minimal additions to Clause 26
o 100BASE-X dual SMF is already happening, and will have applicability
even outside EFM
o However, 100BASE-X SMF will be used in the public access application
o 100BASE-X PCS is transparent to EFM OAM
- Neither "OAM in Frames" nor "OAM on Preamble" require any changes to