Re: FW: STUFF
I'm not quite at the agree to disagree point yet.
Is there really space in the 10gig SMF market for WAN-Ethernet,
LAN-Ethernet and OC-192 POS?
Which Ethernet should be used in the MAN?
What if vendor A markets flavour A in the campus backbone while vendor B
pushes flavour B for the backbone? That doesn't sound much like Ethernet
plug and play.
Is there an inherent reason why WAN-Ethernet (as defined in it's present
very light form) is more expensive than LAN-Ethernet over a given distance,
say 10km?
Should one be called Betamax and the other VHS?
Myles Kimmitt
3Com Corp
"Haile-Mariam, Atikem" <ahmariam@xxxxxxx> on 09/03/99 02:31:20 PM
Sent by: "Haile-Mariam, Atikem" <ahmariam@xxxxxxx>
To: "'HSSG Reflector'" <stds-802-3-hssg@xxxxxxxx>
cc: (Myles Kimmitt/US/3Com)
Subject: FW: STUFF
Re-posting private "musings" for additional comment pre-York...
Atikem Haile-Mariam
Sr. Manager, Technical Marketing
Tyco Electronics (AMP)
> -----Original Message-----
> From: Rich Taborek [SMTP:rtaborek@xxxxxxxxxxxxxxxx]
> Sent: Friday, September 03, 1999 2:20 PM
> To: Haile-Mariam, Atikem
> Subject: Re: STUFF
>
> Hi Atikem,
>
> I looks like we're 100% in agreement as to 2 PHYs, a LAN and a WAN PHY as
> well
> as two separate PARs. I believe that the easiest way to see this happen
is
> to
> settle the HSSG objective of MAC/PLS data rate by setting it to 10.0
Gbps.
> If
> you notice the straw polls that Walt Thirion has taken on this issue, the
> sentiment against 9.58464 Gbps and for 10.0 Gbps keeps growing (see page
4
> of
> the Montreal Speed ad hoc report:
>
http://grouper.ieee.org/groups/802/3/10G_study/public/july99/thirion_1_079
> 9.pdf).
> Once that is settled, it's relatively hard to interpret any of the HSSG
> objectives as supporting SONET and a new Call for Interest to support
> SONET can
> be made. I'll even speak in favor of it!
>
> Please feel free to share this strategy. I believe that it maximizes the
> potential of where Ethernet ends up.
>
> Sorry you can't make it to York. Hope to see you soon.
>
> Best Regards,
> Rich
>
> --
>
> "Haile-Mariam, Atikem" wrote:
>
> > Rich:
> >
> > How goes?? Sorry I can't make it to York but I think it's going to be a
> > great meeting!!! I'm glad to see every one is gravitating to 2
different
> > line rates (PHYs)...The fact is, we have 2 different requirements,
price
> > points etc. that are hard to reconcile.....
> >
> > BTW, I still like my original idea of having 2 different PARs...That
> way, we
> > could truly have low cost Enterprise-centric solutions - right down to
> the
> > component level. It's too cumbersome to do it all in 1 PAR...
> >
> > Also, a single PAR outcome will muddle the marketing message...With 2
> PARs,
> > the marketing spin would be much simpler and would revolve around the
> > following themes...
> >
> > "If you want low cost short run connectivity for aggregating
> your
> > gigabit LAN traffic buy 10GX" Or
> > "If you want longer runs that need to aggregate WAN traffic but
> > 10GY"....
> >
> > I'll admit that we managed to do all this in 1 PAR when it came to
> > 1000Base...However, I am worried we will be bogged down unnecessarily
> while
> > the WAN folks figure out what sub-set of OAMP they really need for
> Ethernet
> > traffic...
> >
> > > 'til then...
> >
> > Best Regards
> >
> > Atikem
> >
> > > -----Original Message-----
> > > From: Rich Taborek [SMTP:rtaborek@xxxxxxxxxxxxxxxx]
> > > Sent: Thursday, September 02, 1999 5:27 PM
> > > To: HSSG
> > > Subject: Re: Long distance links
> > >
> > >
> > > Paul,
> > >
> > > In your Montreal presentation
> > >
> (
http://grouper.ieee.org/groups/802/3/10G_study/public/july99/bottorff_1_0
> > > 799.pdf),
> > > page 5, you show a transponder performing a bridge function between a
> DWDM
> > > photonic network and a L2/L3 WAN access switch. I have a couple of
> > > comments
> > > about this implementation:
> > >
> > > 1) It seems that you require a very specific SONET WAN PHY on both
the
> > > Ethernet
> > > side of the Transponder and WAN side of the L2/L3 access switch.
> > > Specifically,
> > > you require that the Ethernet frames be scrambled NRZ, that the
> MAC/PLS
> > > rate of
> > > at least the switch is 9.58464 Gbps, and that no special symbols be
> used.
> > > Essentially, your requirement is that the "Ethernet" link PHY is the
> same
> > > as
> > > SONET OC-192. Is this not exactly true? If not, please point our my
> > > misconceptions.
> > >
> > > 2) I'll even go along with you if your answer above is "Yes, IEEE
> 9.58464
> > > GiGE
> > > is really OC-192". As a matter of fact, I'll support it in committee
> as an
> > > alternative 10 GbE PHY option, call it the "WX" family of PHY's
(could
> be
> > > different wavelengths). However, this PHY is ill suited for the LAN
> > > environment
> > > and forces every demarcation point between "old Ethernet" and "new
> > > SONENET" to
> > > do protocol conversion.
> > > Besides the OC-192 PHY not being cost effective in the LAN for
reasons
> > > I've
> > > belabored in previous notes to this reflector, an additional cost
> which
> > > cannot
> > > be ignored is the cost/performance penalty assessed by forced
protocol
> > > conversion in ALL LAN environments including LAN environments with no
> WAN
> > > access requirements. Am I wrong about this protocol conversion
> > > requirement?
> > >
> > > 3) It seems to me that your presentation portrays one of many
possible
> > > implementations of 10 GbE use in the WAN. The complete set includes
> WANs
> > > which
> > > do and do not utilize DWDM technology. By your own words you indicate
> that
> > > DWDM
> > > equipment may be code dependent (i.e. proprietary). It seems very
> > > reasonable
> > > then to shield 10 GbE from the special purpose, high cost and
> proprietary
> > > interfaces such as DWDM. Please help enlighten me as to how
> standardizing
> > > a
> > > non-standard WAN PHY as 10 GbE helps Ethernet customers in general?
> > >
> > > 4) As far as implementations go, one possible implementation would be
> to
> > > feed
> > > 10 GbE at 10.0 Gbps directly into the DWDM photonic network. Since
> DWDM is
> > > still relatively in its infancy, I foresee more direct WAN
> implementation
> > > which
> > > may benefit from some of the more cost effective PHYs already
proposed
> for
> > > 10
> > > GbE, especially if common interfaces are developed for these PHYs.
The
> use
> > > of
> > > these PHYs would enable perhaps the most cost effective
> implementations of
> > > metro and wide area DWDM networks which can STILL tie into the
> existing
> > > WAN
> > > infrastructure via routing or bridging. It's not much of a stretch to
> > > envision
> > > WAN access routers with DWDM interfaces on the WAN side and 10 GbE
> > > interfaces
> > > on the LAN side. Is this latter implementation impossible? I think
> not.
> > > What is
> > > the signaling protocol on the DWDM side in this case? The point here
> is
> > > that I
> > > view your DWDM photonic network as only one possible implementation
of
> a
> > > DWDM
> > > photonic network. Please don't encumber the rest of the Ethernet
> community
> > > with
> > > implementation specific and special requirements.
> > >
> > > I have to apologize for being so harsh in my trying to the bottom of
> this
> > > issue. But I believe that my strategy in doing so sooner rather than
> later
> > > will
> > > prove to be beneficial. Please also don't take the issues personally.
> I'm
> > > trying very hard to stick to the issues.
> > >
> > > Best Regards,
> > > Rich
> > >
> > > --
> > >
> > > Paul Bottorff wrote:
> > >
> > > > Dan:
> > > >
> > > > I also think we are getting closer to understanding. A few
comments.
> > > >
> > > > Cheers,
> > > >
> > > > Paul
> > > >
> > > > At 05:49 PM 9/1/99 -0600, DOVE,DANIEL J (HP-Roseville,ex1) wrote:
> > > > >
> > > > >Paul,
> > > > >
> > > > >While we may not be coming closer to agreement (or maybe we are?)
I
> > > > >believe we are at least coming closer to understanding.
> > > > >
> > > > >More in context below...
> > > > >
> > > > >> >So if I understand this model, we have a 10Gig link (campus
> > > backbone)
> > > > >> >that is connected to a campus switch. That switch wants to
> connect
> > > to
> > > > >> >a WAN and thus will have a WAN port that operates at 9.58464 by
> > > using
> > > > >> >its XGMII "hold" signal.
> > > > >>
> > > > >> Provided people built networks to this configuration, then it
> > > > >> works just
> > > > >> fine.
> > > > >> The IEEE has not yet decided to build 2 PHYs. I believe that
> > > > >> the WAN PHY
> > > > >> being talked about does not have a distinct identity from the
LAN
> > > PHY.
> > > > >
> > > > >This is one point at which we clearly have different perspectives.
> I
> > > > >believe that there will be sufficient distinction in cost between
a
> > > > >DWDM laser for the WAN, and a (WWDM or serial) solution that is
> > > > >limited to a few Km for the campus. Otherwise, why do we need an
> XGMII?
> > > >
> > > > I agree that a PHY which included a DWDM laser would have a
distinct
> > > > identity. However, I don't believe this interface is the current
> topic
> > > of
> > > > standardization. How I see the system being built is that the DWDM
> > > network
> > > > will be terminated in a shelf which provides 10 GigE access ports.
> On
> > > one
> > > > side of the shelf will be IEEE standard 10 GigE on the other side
of
> the
> > > > shelf will be a DWDM photonic network. The device in the middle at
> the
> > > > demarcation point will be a transponder/repeater. For a router to
> access
> > > > the photonic network it will attach a 10 GigE interface to the
> photonic
> > > > network access port.
> > > >
> > > > A typical 10 GigE WAN link which attaches to a photonic network
> would be
> > > > built using 3 or more link segments. If you refer to my slides from
> > > > Montreal the 5th slide provides a picture of such a network. The
> link
> > > > segments which attach from the router to the photonic network need
> to
> > > > provide the 9.584640 data rate since this is all the data the
> photonic
> > > > network can carry due to historic reasons. The PHYs in the router
do
> not
> > > > have DWDM photonics.
> > > > >
> > > > >> Because I don't have a good criteria for distinct identity
> > > > >> I've found no
> > > > >> reason to believe the committee should build 2 PHYs. My
> > > > >> assumption is that
> > > > >> any PHY developed may run on SMF and may be deployed in the
> > > > >> wide area. This
> > > > >> is what is currently happening with 1 GigE.
> > > > >
> > > > >Actually, there is LX, SX, CX and 1000BASE-T not to mention a few
> > > > >proprietary links for long-haul 1550nm. There is no reason not to
> > > > >believe that 10G will follow the paradigm that allows multiple
> > > > >PHYs for multiple cost/performance domains.
> > > >
> > > > Access to the photonic network described above can (and will in
some
> > > cases)
> > > > be less than 100 meters. It may use 850, 900, 1300, for 1550 nm
> lasers.
> > > It
> > > > may be serial or CWDM. Finally it may have a different encode that
> the
> > > DWDM
> > > > network (though I dislike this).
> > > > >
> > > > >> >
> > > > >> >I agree that THAT switch will require buffering to handle the
> rate
> > > > >> >mismatch, but that would be required in the event that it has
> more
> > > > >> >than 10 Gigabit links feeding it anyway. This is OK.
> > > > >>
> > > > >> In the configuration I described it is the buffer at a
> > > > >> transponder/repeater
> > > > >> located at the junction between the IEEE segment and the DWDM
> > > > >> segment which
> > > > >> requires buffering to rate match. At this juncture there are
only
> two
> > > > >> ports. One side is the IEEE 10.00 Gbps and the other side is
> > > > >> the 9.9584640
> > > > >> Gbps DWDM cloud. The buffer size covers only the rate mismatch
> not
> > > the
> > > > >> normal overload seen in packet switches. The photonic network
> > > > >> appears as a
> > > > >> new segment in the link between switches, not as a separate
link.
> > > > >
> > > > >This looks like a specific implementation restriction. I doubt
that
> > > > >I would implement it that way.
> > > > >
> > > > >Regards,
> > > > >
> > > > >Dan Dove
> > > > >
> > > > >
> > > > Paul A. Bottorff, Director Switching Architecture
> > > > Enterprise Solutions Technology Center
> > > > Nortel Networks, Inc.
> > > > 4401 Great America Parkway
> > > > Santa Clara, CA 95052-8185
> > > > Tel: 408 495 3365 Fax: 408 495 1299 ESN: 265 3365
> > > > email: pbottorf@xxxxxxxxxxxxxxxxxx
>
> -------------------------------------------------------------
> Richard Taborek Sr. Tel: 650 210 8800 x101 or 408 370 9233
> Principal Architect Fax: 650 940 1898 or 408 374 3645
> Transcendata, Inc. Email: rtaborek@xxxxxxxxxxxxxxxx
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>