Thread Links Date Links
Thread Prev Thread Next Thread Index Date Prev Date Next Date Index

Re: [HSSG] Fw: [hssg] CORRECTED 10GigE LR vs SR


 10GbE LR was first to market for a very simple reason - it had been further
developed than the MMF PMDs, for other applications. BOTH of the MMF PMDs,
LX4 and SR, were later to market because additional development was required
relative to LR. Regardless, SR is now the lowest cost 10G Optical PMD up to
300 meters and LX4 is available to serve existing 300 meter FDDI MMF links,
as it was intended, and both are now deployed in volume based on their value

It is very understandable that many early adopters selected LR as it was the
first PMD available. And the fact the there was a shortage of SR speaks to
it's value to customers once it became available.

Now we have a new challenge, likely 100G. We should focus on selecting PMDs
for that speed which are cost optimized for various reach requirements in
this application space.

Best Regards,
John George

-----Original Message-----
From: Brad Booth
To: STDS-802-3-HSSG@xxxxxxxxxxxxxxxxx
Sent: 8/7/2006 8:36 PM
Subject: Re: [HSSG] Fw: [hssg] CORRECTED 10GigE LR vs SR

One observation is that there were a lot of statements about the
capabilities of MMF and that influenced the decision to have 10GBASE-SR
in 802.3ae, yet SR was not deployed as quickly and as widely as LR.  By
the time the industry learned about some of the issues related to the SR
port type and OM3 MMF, the standard was complete.  HSSG can learn from
this experience when considering whether or not to support MMF and if
so, what reach is required.
I think that it is important to pay attention to the end users like Adam
and Mike Bennett, as they can give the HSSG an indication of the reach
requirements.  Then, the HSSG can try to make its best assessment of the
most cost-effective solution that can satisfy the market demands,
whether the media be twinax, STP, MMF or SMF.


From: Paul Kolesar [mailto:PKOLESAR@xxxxxxxxxxxx] 
Sent: Monday, August 07, 2006 3:14 PM
To: STDS-802-3-HSSG@xxxxxxxxxxxxxxxxx
Subject: Re: [HSSG] Fw: [hssg] CORRECTED 10GigE LR vs SR

if copper fulfills most of your need for short range Ethernet
interconnects, then I assume that the copper you refer to is either
1000BASE-T or 10GBASE-CX4.  These have significantly differing distance
capabilities and media.  The first being 100m on UTP and the second 15m
on twinax.   If both of these suffice, then "sufficient short range
coverage" for Yahoo! means the lesser of the two.  Please confirm or
correct my interpretation, as this can help scope out objectives.   

I disagree that supporting new speeds on MM always causes significant
delay.  The Ethernet standards at both 1G and 10G were published with
both MM and SM PMDs in their initial addenda; both completed
simultaneously.  There was a few month delay in finishing the 1GbE
standard in order to support 1000BASE-LX on MM, and its additional value
to GbE may be questioned since 1000BASE-SX is by far the leading optical
PMD for 1GbE.  But 1000BASE-SX was immediately available as the standard
was finished.  No delay whatsoever.  At 10G, telecoms drove SM PMD
product development prior to 802.3ae publication and 10GBASE-LR and -ER
tapped into that.  Comparatively, MM solutions were developed as 10GbE
unfolded.  And while I believe it is true that initial 10GbE deployments
were primarily -LR, in 2005 MM deployments grew to be half the market as
10G continued to penetrate the data center.  I suspect the lead time
problems with -SR in the past were more an issue of inadequate
forecasting than of product availability.  -SR was and is available from
multiple suppliers.   Demand outstripped the supply as more customers
realized the value in -SR, providing incentive to qualify more of the
available suppliers.  While many of these customers are not the earliest
adopters of 10GbE, such as Yahoo!, they are part of the growing base
that arrives behind the leading edge and represents the bulk of sales.

There were phased introductions of additional PMDs to both GbE and
10GbE.  Later addenda brought about 1000BASE-T, 10GBASE-CX4 (with
10GBASE-T and -LRM in the wings).  Despite stating delay as a cause for
spurn, Yahoo! has apparently deployed these with some fervor, along with
their associated media.  If relative tardiness in standardization were
truly a reason for disdain, Yahoo! should have ignored these.   

At the next higher speed there are technologies available for both MM
and SM that can be either repackaged or reconfigured versions of 10G
technologies.  Given these, I see no inherent delay in standardization
due to inclusion of MM solutions.   

Paul Kolesar
CommScope EnterpriseŽ Solutions
1300 East Lookout Drive 
Richardson, TX 75082 
Phone:  972.792.3155
Fax:      972.792.3111
eMail:   pkolesar@xxxxxxxxxxxxx

Adam Bechtel <abechtel@xxxxxxxxxxxxx> 

08/07/2006 12:10 PM 

Please respond to
Adam Bechtel <abechtel@xxxxxxxxxxxxx>



Re: [HSSG] Fw: [hssg] CORRECTED 10GigE LR vs SR


We (Yahoo!) don't use SR either, and we definitely are a datacenter
centric business.  In addition to Lane's reasons below: 
 1. Copper technologies have replaced 95% of my need for short range
optics and cabling (the remaining 5% being storage related).   
 2. There is always a significant delay to support new speeds on MM
(e.g., GE, 10GE).  We adopted 10GE before SR was available. 
 3. In the 2004-5 timeframe we were experiencing a 3x leadtime on
procuring SR vs. LR optics.  That has since changed. 
In the end, the flexibility of laying SMF in our datacenters outweighed
the cost difference.   


From: Paul Kolesar [mailto:PKOLESAR@xxxxxxxxxxxx] 
Sent: Monday, August 07, 2006 9:35 AM
To: STDS-802-3-HSSG@xxxxxxxxxxxxxxxxx
Subject: [HSSG] Fw: [hssg] CORRECTED 10GigE LR vs SR 

John DAmbrosia asked that I forward this thread to the 802.3 HSSG
reflector so that discussions could continue after the EA-facilitated
HSSG reflector shuts down.  I have modified the subject line to make it
more to the point. 

Paul Kolesar
CommScope EnterpriseŽ Solutions
1300 East Lookout Drive 
Richardson, TX 75082 
Phone:  972.792.3155
Fax:      972.792.3111
eMail:   pkolesar@xxxxxxxxxxxxx

----- Forwarded by Paul F Kolesar/CommScope on 08/07/2006 11:28 AM -----

"John DAmbrosia" <jdambrosia@xxxxxxxxxxxxxxxxxxx> 

08/04/2006 08:28 PM 



RE: [hssg] CORRECTED (RE: 10GigE LR vs SR (RE: [hssg] Update of CFI
Presentation to IEEE))



Please note that the Ethernet Alliance facilitated HSSG reflector is in
the process of being shut down.   
The HSSG Reflector has been set up and is ready to go.  Please go to the
URL below for directions on how to join the IEEE 802.3 HSSG Reflector.

In addition, please note that the HSSG website is up and running, and
may be viewed at 
Upon joining I would suggest forwarding this message to the IEEE 802.3
reflector.  The cost model is a big one that the SG must address. 
Hope you had a good vacation. 



From: PKOLESAR@xxxxxxxxxxxx [mailto:PKOLESAR@xxxxxxxxxxxx] 
Sent: Friday, August 04, 2006 7:16 PM
To: Lane Patterson
Cc: hssg@xxxxxxxxxxxxxxxxxxxx
Subject: Re: [hssg] CORRECTED (RE: 10GigE LR vs SR (RE: [hssg] Update of
CFI Presentation to IEEE)) 

sorry for the delayed response.  Vacationitus interuptus.   

I appreciate the particular circumstances of your business and how they
lead to the choices you have made.  But as you say, your center is not
like that of the typical data center.   

While the discussion of price is a sensitive issue, and direct prices
are not to be mentioned on the reflector, I have confirmed with my PLM
that those you stated (in your previous version which you have since
corrected below) are two orders of magnitude too large.  Perhaps the
decimal point was left out.  I bring this up because such large
discrepancies provide extreme distortion to the view.   In addition, it
is not really possible to do a relative cost assessment when absolute
costs of one item are compared to percentage cost differences of another
item.  What is needed is for all to be distilled to the same units ($),
then made into relative costs for comparison.   

I agree that MM cable costs more than SM cable, and that the relative
cost for the same cable construction is in the ballpark of what you
stated for very high count cables (3 to 4x).   

However, one of the challenges in making sensible relative cost
comparisons is picking a set of assumptions that is relevant.  In this
discussion, than means comparing similar units of scale.  For example,
if one installs a very high fiber count cable that can support many
channels, then one should not expect the differential in cost between a
single channel's worth of PMDs to be used in justifying the added cost
of the entire cable.  It needs to be broken down to the same relative
units.  In this case, that means the differential between 2 strands of
the MM cable compared to two strands of the SM cable, for the channel
length of interest, plus the associated connector, panel and patch cord
hardware that make up the channels.  Here, the channel lengths of
interest must be confined to those that can be supported by both PMDs,
since lengths exceeding the capability of one of the PMDs are out of
scope.  If you examine the cost models from on that basis, perhaps you
will have a better appreciation for my statements.   

The cross connect lengths of 150m that you mentioned are not clear to
me.  Is that the length from the equipment to the cross connect or the
length of the entire channel from equipment thru cross connect to
equipment?  If the latter, then -S with OM3 will certainly work.  If the
former, which is what I think you likely meant, then it is a matter of
connection loss vs supportable distance.   Solutions exist that can
support 300m channels thru a cross connect for 10GBASE-S.   

Paul Kolesar
CommScope EnterpriseŽ Solutions
1300 East Lookout Drive 
Richardson, TX 75082 
Phone:  972.792.3155
Fax:      972.792.3111
eMail:   pkolesar@xxxxxxxxxxxxx 

"Lane Patterson" <lpatterson@xxxxxxxxxxx> 

07/25/2006 04:03 PM 




[hssg] CORRECTED (RE: 10GigE LR vs SR (RE: [hssg] Update of CFI
Presentation to IEEE))



My apologies to John and to the list for inadvertently putting pricing
data in my last post, it won't happen again :-) 

I have corrected this below, so folks who wish could reply to the

-----Original Message-----
From: Lane Patterson 
Sent: Monday, July 24, 2006 5:53 PM
To: 'PKOLESAR@xxxxxxxxxxxx'; 'hssg@xxxxxxxxxxxxxxxxxxxx'
Subject: 10GigE LR vs SR (RE: [hssg] Update of CFI Presentation to IEEE)


Very much appreciate your comments on this.  As an Internet exchange
point, I realize we're probably not representative of the typical
single-company data center environment here, but wanted to share the
reasons why SR did not make it into our operating environment.
Apologies in advance if this is a bit too off-topic for the HSSG

1.  We already had legacy 62.5 micron Multimode as well as SMF pulled in
conduits approx 1.5km in our multi-building campus sites 
2.  On these campus conduit builds, MMF cost us more than 4x the price
per linear foot, compared to SMF. 
3.  Within our data centers (sized at roughly 100K-230K sq ft),
cross-connect lengths routinely hit 150m 
4.  There's tremendous OpEx involved in standardizing on a new type of
fiber--I am checking now to see what's involved in supporting OM3 and it
is about a 6 month process to evaluate, stock, productize, and train
5.  Most of our 10GigE customers are ISPs using Cisco or Juniper
routers, and commonly request LR 
6.  Our cost for SR is only about 30% less than cost of LR, which is not
enough to justify stocking two types of parts, spares, etc. when we can
standarize on LR-only and simplify OpEx and pre-provisioning and support


Lane Patterson 
 <mailto:lane@xxxxxxxxxxx> lane@xxxxxxxxxxx 
Chief Technologist 
Equinix, Inc. 
+1 650-513-7012 (w) 
+1 408-829-6464 (c) 
skype:  lane_p 

-----Original Message-----
From: PKOLESAR@xxxxxxxxxxxx [mailto:PKOLESAR@xxxxxxxxxxxx] 
Sent: Friday, July 21, 2006 4:59 PM
To: Lane Patterson; hssg@xxxxxxxxxxxxxxxxxxxx
Subject: RE: [hssg] Update of CFI Presentation to IEEE

I find it odd that Equinix has not realized the advantages of deploying
SR.  While its distance capability is rather limited on legacy multimode
fibers, it is rated up to 300 m on OM3 (a.k.a. 850nm laser-optimized
50um) fiber, a distance sufficient to serve the vast majority of both
in-building backbones and data centers.   

From recent presentation materials from a major Ethernet networking gear
supplier, 10GbE multimode port shipments grew to equal singlemode port
shipments in 2005.   

From this I conclude that multimode is providing value to a significant
percentage of customers.  That value includes the fact that those who
have installed OM3 cabling are able to deploy either SR or LX4 to 300 m.
This freedom allows the customer to choose from these PHYs based on
several criteria including not only cost, but also availability, and
port-type homogeniety considerations.   

In most cases cost will be the primary factor.  While it is true that
over time the cost differential between port types compresses, the
differential between SR and either LR or LX4 has been, and continues to
be, quite significant, easily justifying the deployment of OM3 cabling
for new buildouts.   

Data center cabling must often be deployed under tight schedules.  This
has lead to great acceptance of solutions that provide cabling in
predetermined lengths terminated with array connectors at the factory.
The array terminations are compact and allow easier deployment of the
pre-terminated cables.  The arrays plug into fanout modules or
hydra-cords for administration of duplex circuits.  Factory termination
can provide high-quality polish, and fanouts provide worry-free
transmit-to-receive signal routing (a.k.a. polarity), along with very
rapid turn up in the field because the installer simply plugs components
together instead of handling the termination process on site.  Virtually
all of our data center projects deploy this type of solution. 

There is an additional advantage to these cabling solutions.  They
protect the customer's investment by providing a migration path for
support of parallel fiber applications, such as those defined by
InfiniBand.  One simply removes the fanout and administers the parallel
application using array patch cords, thus reusing the cables.   

TIA TR-42 has standardized these types of structured cabling solutions
in TIA-568-B.1-7 "Commercial Building Telecommunications Cabling
Standard, Part 1 - General Requirements, Addendum 7 - Guidelines for
Maintaining Polarity Using Array Connectors".   This standard provides a
useful reference for committees that develop parallel fiber
applications.   The parallel methods defined within this standard
support all the parallel applications of Fibre Channel, OIF, and

An increasing installation rate of these solutions is building the
installed base of cabling that not only fulfills the immediate demands
of tight construction schedules, but also protects the customer's
investment by providing the flexibility to be easily reconfigured for
future parallel applications.  And while this solution offers the same
benefits to both multimode and singlemode media, 850nm laser-optimized
50um fiber represents about 80% of the cabling mix in our sales.   

Given that the commonly held view regarding deployment of a higher speed
Ethernet is that it will occur initially within data centers, it would
be an obvious error not to define a PHY/PMD that operates over this
cabling infrastructure. 

Paul Kolesar
CommScope EnterpriseŽ Solutions
1300 East Lookout Drive 
Richardson, TX 75082 
Phone:  972.792.3155
Fax:      972.792.3111
eMail:   pkolesar@xxxxxxxxxxxxx 

"Lane Patterson" <lpatterson@xxxxxxxxxxx> 

07/20/2006 05:15 AM 


"David Martin" <dwmartin@xxxxxxxxxx>, <hssg@xxxxxxxxxxxxxxxxxxxx> 


RE: [hssg] Update of CFI Presentation to IEEE



As an end user, I couldn't agree more.  Our view is that 10GigE has
already radically changed the economics of data center/campus (LR) and
metro (ER/ZR) connectivity, compared to the OC192 alternative, and
somewhat limited scalability of LAG and ECMP.  I would expect that 100G
would be equally successful at a 4x/2.5x benefit to cost ratio.

I also agree with Aaron and Bruce's comments about PMD/PHY--the 2-10km
range serves data center, in-building riser fiber, and campus
environments nicely.  Most early uses of 100G links will be for such
aggregated trunking.  In contrast, with our 10GigE experience, SR was
almost completely useless with its distance limitations and eventual
marginal price diff with respect to LR.


-----Original Message-----
From:   David Martin [  <mailto:dwmartin@xxxxxxxxxx>
Sent:   Wed Jul 19 10:58:33 2006
To:     hssg@xxxxxxxxxxxxxxxxxxxx
Subject:        RE: [hssg] Update of CFI Presentation to IEEE


Several comments were made during the CFI last night that 10GigE hasn't
yet achieved the traditional "10x rate for 3x the cost" economic
feasibility, and as such it's unlikely that a higher speed Ethernet rate
would be any more successful.

Some other comments were made that since 10GigE (and quite likely the
next rate) broke new ground as network infrastructure, rather than
traditional NICs and switch ports, the "10x rate for 3x the cost" rule
of thumb should be revisited.

In carrier transport networks, the equivalent rule has been "4x rate for
2.5x the cost". Just thought I'd pass that along for reference for when
this issue is considered.


David W. Martin
Nortel Networks
dwmartin@xxxxxxxxxx <  <mailto:dwmartin@xxxxxxxxxx>
+1 613 765 2901 (esn 395)


From: John DAmbrosia [  <mailto:jdambrosia@xxxxxxxxxxxxxxxxxxx>
Sent: Wednesday, July 19, 2006 12:37 PM
To: hssg@xxxxxxxxxxxxxxxxxxxx
Subject: [hssg] Update of CFI Presentation to IEEE


Last night's presentation went extremely well.  Approximately 200 to 220
people were present throughout the presentation.

After the presentation, the following straw polls were asked:

Straw Poll #1 - (For the Call-For-Interest)

Should a Study Group be formed for "Higher Speed Ethernet"?


Yes - 147

No - 9

Abstain - 31

Straw Poll #2 (For Participation)

I would participate in the "Higher Speed" Study Group in IEEE 802.3.

Tally: 108

Straw Poll #3 (For Participation)

My company would support participation in the "Higher Speed" Study Group
in IEEE 802.3

Tally: 76

Thus, the results were very positive and encouraging.  This does not
mean that the Study Group has been formed yet. 

A motion will be made at the IEEE 802.3 Closing Plenary on Thursday.
Thus, for those individuals who registered and are at the IEEE Plenary
this week; please make sure you stay until the motion has been made and
the vote taken.  If the motion is successful on Thursday, then a request
will be made to the IEEE 802.3 EC for approval of the formation of the
study group.

John D'Ambrosia