Re: [EFM] Changes to 100BASE-X and 1000BASE-X PCS, 10G RS
Jonathan, just to clarify re:
> principal reasons for standardizing 100M and 1G optics at
> 10km is that the
> parts available from the industry (when we started) could not
> be assured to
> be mutually interoperable. In many cases, under many
> conditions, they were
> probably interoperable. To create a standard that assures backward
> interoperability with parts that were themselves
> not-necessarily-interoperable... well, I think that this
> might be an effort
> in futility.
802.3 says that 1000BASE-LX is interoperable to 5 km on SMF. D3.1 says that 1000BASE-LX10 is is interoperable with itself to 10 km and with 1000BASE-LX to 5 km. If interested in the detail of how that can be, see latest link model file http://www.ieee802.org/3/efm/public/tools/EFM0_0_2.7.xls .
D3.1 doesn't comment on how the pre-standard "stretched 1000BASE-LX" parts perform in the range between 5 and 10 km. Obviously there was interest in this subject or EFM would not have objectives to address it.
I was more addressing the question of logic changes causing interoperability and other issues whatever the link length.
Piers
> -----Original Message-----
> From: owner-stds-802-3-efm@majordomo.ieee.org
> [mailto:owner-stds-802-3-efm@majordomo.ieee.org]On Behalf Of Jonathan
> Thatcher
> Sent: 03 March 2004 19:14
> To: stds-802-3-efm@ieee.org
> Subject: RE: [EFM] Changes to 100BASE-X and 1000BASE-X PCS, 10G RS
>
>
> With great fear I here tread....
>
> As we prepare for this discussion a 2 weeks, let us remember
> that one of the
> principal reasons for standardizing 100M and 1G optics at
> 10km is that the
> parts available from the industry (when we started) could not
> be assured to
> be mutually interoperable. In many cases, under many
> conditions, they were
> probably interoperable. To create a standard that assures backward
> interoperability with parts that were themselves
> not-necessarily-interoperable... well, I think that this
> might be an effort
> in futility.
>
> In short, even if we choose to remove the OAM requirements,
> there is no
> assurance that even with the an identical PCS that the parts
> will "play
> nice."
>
> For my part, if we were going to allow OAM to be an option, I
> would strongly
> prefer that it be an option like 802.3ad, which a customer can readily
> identify as a supported feature on a spec sheet, and not an
> option that is
> buried in a PIC table and not readily exposed to the buyer.
> Yes, I realize
> that 802.3ad was a project, not a clause. Yes, I understand that doing
> anything like this with OAM is not possible at this stage.
> That would have
> required a separate project.
>
> jonathan
>
> > -----Original Message-----
> > From: owner-stds-802-3-efm@majordomo.ieee.org
> > [mailto:owner-stds-802-3-efm@majordomo.ieee.org]On Behalf Of Howard
> > Frazier
> > Sent: Wednesday, March 03, 2004 10:38 AM
> > To: stds-802-3-efm@ieee.org
> > Subject: 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: <piers_dawe@agilent.com>
> > To: <benjamin.brown@ieee.org>, <stds-802-3-efm@ieee.org>,
> > <stds-802-3@ieee.org>
> > Ben,
> >
> > 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
> > http://www.ieee802.org/3/smfx_study/index.html 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
> > <http://www.ieee802.org/3/efm/public/mar02/minutes_03_2002.pdf>
> > http://www.ieee802.org/3/efm/public/mar02/minutes_03_2002.pdf
> > 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
> > <http://www.ieee802.org/3/minutes/mar02/minutes_0302.pdf>
> > http://www.ieee802.org/3/minutes/mar02/minutes_0302.pdf :
> > 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
> > <http://www.ieee802.org/3/smfx_study/public/jonsson_1_0302.pdf>
> > http://www.ieee802.org/3/smfx_study/public/jonsson_1_0302.pdf
> >
> > Scope:
> > - Make amendment to Clause 26, 100BASE-FX, to include a
> > 100Mbps dual SMF
> > PMD
> >
> > Broad Market Potential Broad Market Potential
> > ...
> > 100BASE-X SMF is main candidate for volume applications in:
> > - Residential (FTTH)
> > - Commercial (SME, Shopping malls, etc.)
> > - Industrial ( <http://ethernet.industrial-networking.com>
> > http://ethernet.industrial-networking.com)
> > 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)
> >
> > Compatibility
> >
> > 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
> > space
> > o 100BASE-X PCS is transparent to EFM OAM
> > - Neither "OAM in Frames" nor "OAM on Preamble" require any
> changes to
> > 100BASE-X PCS
> >
> > Piers
> >
>