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Re: [HSSG] Reach Objectives: distribution of reaches

Gentle People:

    I would be very careful about interpreting or using the work or
conclusions of the 802.3ae project. Most of this work was completed
in the environment of extreme excess exuberance of the internet technology
boom. In the resulting bust many of the product marketing claims never
came true. Please note that most of the most aggressive players from the 802.3ae
effort are no longer present, their enterprises being handed over to the state's
receiver. For those that don't agree: What is the volume of shipment of the
10G WAN PHY these days?

Thomas Dineen

See in line...

-----Original Message-----
From: Drew Perkins [mailto:dperkins@xxxxxxxxxxxx]
Sent: 23 August 2006 08:53
To: STDS-802-3-HSSG@xxxxxxxxxxxxxxxxx
Subject: Re: [HSSG] Reach Objectives

Why? Because the debate has been had repeatedly for every 
generation of technology that has come and gone and will 
probably be had for every generation that is yet to come. The 
underlying technology changes and that will change the answer 
in terms of where the breakpoints lie between different 


Another big thing that changes is the set of 
people in the room and different groups will always come up 
with different answers based on their different perspectives. 
But one thing that I believe changes very little from 
generation to generation is the reach between different 

Not true.  802.3ae like previous generations of Ethernet was primarily about campus and general-purpose wiring, with an attempt to connect to the WAN.  In the context of HSSG, in my opinion, in the nearer term, the very fat routes for which 10G*Cl.43LAG are insufficient are WITHIN supercomputer rooms and similar.  In the future, the number of fat routes going to another supercomputer room in another city may rise above our threshold of interest.  I just don't see a significant number of campuses with TWO tightly coupled top-end supercomputers or monster routers on the one campus, any time soon.  So I see HSSG's primary interest as truly short links - forget the campus!

My comments are mostly influenced by my perspective on 
telecommunications applications, but I suspect the same thing 
mostly applies to datacenters too. The shape of the histogram 
of the number of links plotted vs. the length of those links 
probably stays roughly constant. Where the breakpoints are of 
greatest cost effectiveness between different fundamental 
technologies will move depending on bit rate, but to the 
first order the number of PMDs probably remains roughly equal.

Looked at that way, the distribution is very broad without very clear break points.  The 802.3ae study of all this was unsatisfactory because even after all the study, it seemed like a judgement call (apart from the 40 km choice for the then repeater hut spacing).  By giving into a natural wish for "just a few more meters" when the technology wasn't developed enough for a consensus understanding of the costs and engineering detail, we ended up with a PMD set that's simply poor for the equipment room: too power hungry.

And if one then filters the distribution of links to find the distribution of fat (super-sized?) routes, I believe the convex distribution becomes more of a bathtub.

My thoughts are further influenced by my expectation that for 
multi-km reaches we'll likely end up with Nx10G (or N/2x20G) 
WDM PMDs. The smaller the N and the larger the bit rate, the 
more the breakpoints are likely to move around.
Drew Perkins
Chief Technology Officer
Infinera Corporation
1322 Bordeaux Drive
Sunnyvale, CA  94089
Phone:  408-572-5308
Cell:       408-666-1686
Fax:        408-904-4644
Email:    dperkins@xxxxxxxxxxxx

From: Brad Booth [mailto:bbooth@xxxxxxxxxxxxx] 
Sent: Tuesday, August 22, 2006 10:56 AM
To: STDS-802-3-HSSG@xxxxxxxxxxxxxxxxx
Subject: Re: [HSSG] Reach Objectives
Excuse my ignorance, but why?  When 10G started, this was an 
important debate.  If they had stuck with the number of PMDs 
in 802.3z, then there would have only been two PMDs.  The 
study group needs to define the markets that it wants to 
satisfy, and only then when the study group becomes a task 
force can the group decide on the actual number of PMDs required.

From: Drew Perkins [mailto:dperkins@xxxxxxxxxxxx] 
Sent: Tuesday, August 22, 2006 10:45 AM
To: Brad Booth; STDS-802-3-HSSG@xxxxxxxxxxxxxxxxx
Subject: RE: [HSSG] Reach Objectives
I have a simple proposal to save everyone a lot of time. 
Let's make the baseline plan to stick with exactly the same 
number of PMDs with exactly the same reaches as 10GbE. They 
have all been developed to fit someone's requirements. We 
should have a very high hurdle to eliminate any of these or 
add to them.
Drew Perkins
Chief Technology Officer
Infinera Corporation
1322 Bordeaux Drive
Sunnyvale, CA  94089
Phone:  408-572-5308
Cell:       408-666-1686
Fax:        408-904-4644
Email:    dperkins@xxxxxxxxxxxx

From: Brad Booth [mailto:bbooth@xxxxxxxxxxxxx] 
Sent: Tuesday, August 22, 2006 10:19 AM
To: STDS-802-3-HSSG@xxxxxxxxxxxxxxxxx
Subject: Re: [HSSG] Reach Objectives
The 10km vs. 2km debate occurred in 802.3ae.  It was 
determined that the solution for 2km was virtually the same 
as that for 10km; therefore, the task force felt it would be 
better to select only one of those reaches and 10km was it.  
If there is a desire for 2km and 10km reaches in HSSG, then 
in my humble opinion, those wishing to support will need to 
bring justification forward as to why the study group should 
consider possibly increasing the number of PHYs.

From: Frank Chang [mailto:ychang@xxxxxxxxxxx] 
Sent: Tuesday, August 22, 2006 9:19 AM
To: STDS-802-3-HSSG@xxxxxxxxxxxxxxxxx
Subject: Re: [HSSG] Reach Objectives
I agree datacenter for up to 100m. How about 10GigE LR 
disctance (10km) or campus 2km discussed earlier? 
-----Original Message-----
From: Petar Pepeljugoski [mailto:petarp@xxxxxxxxxx]
Sent: Tuesday, August 22, 2006 6:02 AM
To: STDS-802-3-HSSG@xxxxxxxxxxxxxxxxx
Subject: Re: [HSSG] Reach Objectives


I believe that the Data Center distances should be 100m and 300m. 

Petar Pepeljugoski
IBM Research
P.O.Box 218 (mail)
1101 Kitchawan Road, Rte. 134 (shipping)
Yorktown Heights, NY 10598

e-mail: petarp@xxxxxxxxxx
phone: (914)-945-3761
fax:        (914)-945-4134
John DAmbrosia <jdambrosia@xxxxxxxxxxxxxxxxxxx> 
08/22/2006 12:37 AM 
Please respond to
John DAmbrosia <jdambrosia@xxxxxxxxxxxxxxxxxxx>
Subject[HSSG] Reach Objectives


We have had some conversation on the reflector regarding 
reach objectives.  Summarizing what has been discussed on the 
reflector I see the following - 
Reach Objectives 
Long-Haul   --> 100+ km 
Metro       --> 10+ km 
Data Center --> 50m & 300m 
Data Center Reach Segregation 
Horizontal runs 
Vertical risers 
Use this data to identify a single low-cost solution that 
would address a couple of the reach objectives 
Other Areas 
During the course of the CFI there were individuals who 
wanted Backplane Applications kept in for consideration, but 
I have not heard any further input in this area.  Are there 
still individuals who wish to propose Backplane as an objective?