All -
Seeing the traffic on this email
thread, is it time to consider Alessandro's possible scenario c) [excerpt from his email
dated 7/31/8]
… My
concern now shifts to how to resolve the impasse without impacting the
standard. … c) We give up the
objective (I can't believe I am writing this:-) because we can't get
consensus. At that point I think the market will decide.
Would be an interesting data
point to see where the TF stands on this option.
--------------------------------------------
Thananya
Baldwin
Director of Strategic Programs
Ixia
thananya@xxxxxxxxxxx
-----Original
Message-----
From: Chris Cole [mailto:chris.cole@xxxxxxxxxxx]
Sent: Thursday, August 14, 2008 6:16
PM
To:
STDS-802-3-HSSG@xxxxxxxxxxxxxxxxx
Subject: Re: [802.3BA] Discussion on 40G for ="" 10 km
SMF
Mori-san,
Let me address the size
questions first.
Double XENPAK size is one
alternative for a quick development program for 40GE-CWDM PMD using
existing components, although other alternatives are
possible.
Let's assume that 2x XENPAK
size is about 120mm x 72mm. This size needs to accommodate the
functionality of 4 XFPs and a Mux/DeMux.
XFP size is 70mm x 18mm, so
four XFPs use 2/3 of the available area.
This leaves 50mm x 72mm for the
Mux/DeMux. One example of a TFF Mux/DeMux was presented in paatzsh_01_0708
with size given on page 3 as 13mm x 13mm, which leaves plenty of room for
fiber routing, etc.
So your concern about having
to push components into the module was unfounded.
By comparison, 40G Serial GPPO
based telecom modules are now moving to 4.5" x 3.5" size (about 114mm x
90mm,) i.e. very comparable in size to the above.
With respect to cost, I do not
understand your specific question about "cost down technology." What you
kindly clarify what you would like me to comment on?
However, more generally I am
confused as to what you are trying to accomplish with your 40GE-CWDM cost
questions. There is agreement, as confirmed by your emails that the cost
using existing technology is between 4x and 8x 10GE LR. Further, the
initial cost in 2010 is projected as about 6x 2010 10GE LR, as in
traverso_02_0708 and in several emails from Serial proponents, for example
in Takai-san's
7/31/08 email. With
incremental cost reduction investment this cost may asymptotically
approach 4x of 10GE LR cost decreasing over time (NOT 4x of 10GE LR in a
specific year like 2010.)
So what exactly is the
motivation for debating a point that has agreement?
Chris
-----Original
Message-----
From: Kazuyuki Mori [mailto:mori.kazuyuki-1@xxxxxxxxxxxxxx]
Sent: Thursday, August 14, 2008 8:25
AM
To:
STDS-802-3-HSSG@xxxxxxxxxxxxxxxxx
Subject: Re: [802.3BA] Discussion on 40G for ="" 10 km
SMF
Chris-san
Thank you for your reply, but
I found no answers for my questions about 4x10G CWDM module in your
comment.
- Cost down technology
- Module size (double XENPAK is correct?)
And I'd like to ask below
question;
- How to push 4-TOSAs, 4-ROSAs and 2-TFFs into the
module?
Thanks,
Kazuyuki Mori
----- Original Message
-----
From:
"Chris Cole" <chris.cole@xxxxxxxxxxx>
To:
<STDS-802-3-HSSG@xxxxxxxxxxxxxxxxx>
Sent: Thursday, August 14, 2008 9:02
AM
Subject: Re:
[802.3BA] Discussion on 40G for ="" 10 km SMF
Mori-san,
Thank you for clarifying that
direct connection means the use of a GPPO
adaptor instead of GPPO cable between
the SerDes IC PCB and the optics.
With respect to your specific
comments and questions:
1) Cost
You are correct that 802.3ba
TF consensus is that 40GE-CWDM cost will be
between 4x and 8x of
10GE-LR.
HOWEVER this is relative to
10GE-LR cost over time. So a constant cost
multiplier ratio like 4x, means that
the absolute cost is decreasing by
following the decrease in the cost of
10GE-LR.
Your statement that no CWDM
solution will realize less then 4x cost
reduction is misleading, as already
pointed out by Steve Trowbridge in
his 8/4/08 reflector
email.
You are comparing a falling
cost ratio of 40GE-Serial against a constant
cost reference (10GE LR in 2010,)
versus a constant cost ratio of
40GE-CWDM (4x) against a falling cost reference (10GE-LR
over time.)
This is not apples-to-apples.
So let's do a fair
apples-to-apples comparison. On page 15 of
traverso_02_0708, 40GE-Serial with GPPO
IF cost (your reflector email
proposal) in 2010 is 5.9x 2010 10GE LR cost, and in 2012
is 3.7x 2010
10GE LR cost. This represents a huge 8x cost reduction from the
cost of
40GE-Serial in 2008, and then very steep cost reduction from 2010
to
2012
(1.6x.)
On the same page, 40GE-CWDM
cost in 2010 is 5.9x 2010 10GE LR cost, and
in 2012 is 4.9x 2010 10GE LR cost.
Since just the cost of 10GE LR will
drop from 1x in 2010 to 0.73x in 2012,
this means you are claiming that
in 2012 40GE-CWDM cost is 6.7x 2012 10GE LR cost, i.e.
the cost
multiplier is increasing! This will NOT be the case, and would
only
happen if
there was NO cost reduction investment in 40GE-CWDM.
A much more accurate cost
reduction prediction is that if 40GE-CWDM cost
in 2010 is 5.9x 2010 10GE LR cost, then
in 2012 it is 4.3x 2010 10GE LR
cost, i.e. following 10GE LR cost
decrease.
If the same type of
aggressiveness is used to predict CWDM cost as is
being used for Serial cost predictions,
then 40GE-CWDM cost in 2010 is
5x 2010 10GE LR cost, and in 2012 is 3.7x 2010 10GE LR
cost (less then
4x!)
40GE-Serial has no cost
advantage over 40GE-CWDM in the foreseeable
future. Contrary to many statements,
40GE-CWDM cost will fall below 4x
10GE LR cost if the cost reference is 10GE LR in a given
year, like 2010
which is what is used for 40GE-Serial cost
predictions.
2) Size, form
factor
You are making an unfair
comparison of what is possible for 40GE-Serial
advanced technology with a huge
investment, to what is possible with
40GE-CWDM off the shelf technology with
modest investment.
To package today's 40GE-Serial
technology (GPPO IF ICs and Optics) in a
pluggable form factor, something like
double XENPAK is required. A
XENPAK or X2 size is not feasible.
As I commented in my 7/31/08
email to Takai-san, if we are to make a
fair comparison of advanced technology
with huge investment, CWDM has a
size advantage over Serial. CWDM CDRs can be separated
from the optics,
and an un-retimed form factor like QSFP becomes possible with
optics
integration. For Serial, the SerDes always have to be packaged with
the
optics
leading to a size disadvantage for both space and thermal
reasons.
3) CWDM optics
connection
The proposal for quick time to
market 40GE-CWDM product is to use
existing discrete 10G OSAs (with DFBs
on the CWDM grid) connected with
separate fibers to discrete TFF, similar to what was
presented in
paatzch_01_0708 but for CWDM.
Thank you
Chris
-----Original
Message-----
From: Kazuyuki Mori [mailto:mori.kazuyuki-1@xxxxxxxxxxxxxx]
Sent: Wednesday, August 13, 2008 9:50
AM
To:
STDS-802-3-HSSG@xxxxxxxxxxxxxxxxx
Subject: Re: [802.3BA] Fwd: Re: [802.3BA] Discussion on
40G for ="" 10 km
SMF
Chris-san,
Actually, a female-female
adaptor is used for GPPO connection. I know
the
cost of every such GPPO component is
relatively high when compared to
10GE
LR XFP component cost.
This kind of RF interconnection technologies enables us
to reduce size
(XENPAK or X2) and cost of 40GE Serial modules.
Anyway, I don't know the
details of 4x10G CWDM module.
1)Cost
TF consensus are 4x-8x of 10GE LR and
no solution to realize under
4x.
2)Size, form factor
What kind of form factor do you use,
double size of XENPAK?
3)Connection between optics
Do you use discrete
optics? Do you use fiber to connect between
optics?
Thanks,
Kazuyuki Mori
----- Original Message -----
From: "Chris
Cole" <chris.cole@xxxxxxxxxxx>
To:
<STDS-802-3-HSSG@xxxxxxxxxxxxxxxxx>
Sent: Wednesday, August 13, 2008 4:01
AM
Subject: Re:
[802.3BA] Fwd: Re: [802.3BA] Discussion on 40G for ="" 10
km
SMF
Mori-san,
The only commercially
available PCB edge mount GPPO connectors I know
have male polarity, which is the same
as XLMD GPPO connectors.
Are you developing commercial
female polarity PCB GPPO connectors that
could be directly connected to the XLMD
GPPO connectors?
Or by direct connection do you
mean that instead of flexible
female-female polarity GPPO cable you use rigid
female-female polarity
GPPO bullet?
As you know, the cost of every
such GPPO component is significant when
compared to 10GE LR XFP component
costs.
Thank you
Chris
-----Original
Message-----
From: Kazuyuki Mori [mailto:mori.kazuyuki-1@xxxxxxxxxxxxxx]
Sent: Tuesday, August 12, 2008 12:25
AM
To:
STDS-802-3-HSSG@xxxxxxxxxxxxxxxxx
Subject: Re: [802.3BA] Fwd: Re: [802.3BA] Discussion on
40G for ="" 10 km
SMF
Chris-san,
We connect the PCB edge mount
GPPO connectors and GPPO connectors on the
XLMD optics directly.
Therefore we can eliminate the GPPO cable and
reduce
module size.
Thanks,
Kazuyuki Mori
----- Original Message -----
From: "Chris
Cole" <chris.cole@xxxxxxxxxxx>
To:
<STDS-802-3-HSSG@xxxxxxxxxxxxxxxxx>
Sent: Tuesday, August 12, 2008 3:50
PM
Subject: Re:
[802.3BA] Fwd: Re: [802.3BA] Discussion on 40G for ="" 10
km
SMF
Hello Mori-san,
Thank you for continuing to
fill in the details of the 40GE-Serial
baseline
proposal.
You correctly point out that
edge mount type GPPO connectors are
commercially available. Various types
of such edge connectors are used
on
all 40G GPPO IC and Optics packages, and ship in 10Ks volume
into
telecom
applications.
Is is reasonable to assume
that the interconnect between the PCB edge
mount
GPPO connectors and GPPO conectors on
the XLMD optics are GPPO cables,
similar to cables used in 40G modules today, for example
as shown in the
left hand photograph on page 8
of traverso_02_0708?
Chris
________________________________
From: Kazuyuki Mori
[mailto:mori.kazuyuki-1@xxxxxxxxxxxxxx]
Sent: Mon 8/11/2008 10:37
PM
To:
STDS-802-3-HSSG@xxxxxxxxxxxxxxxxx
Subject: Re: [802.3BA] Fwd: Re: [802.3BA] Discussion on
40G for ="" 10 km
SMF
Hello Chris-san,
Sorry for our insufficient
information for RF interconnection. In case
of
XLMD, we use an edge mount type GPPO
connector at the end of PCB, so we
can
apply the SMT type package for SerDes
as shown on the right side of page
6
of traverso_02_0708. We already
confirmed the characteristics of this RF
interconnection; the result shows 50GHz
BW. As you know well, the edge
mount
type GPPO connector is already commercially
available.
Thanks,
Kazuyuki Mori