RE: [10GBASE-T] Proposed modification to PAR scope
From Chris Di Minico...
-----Original Message-----
From: CDimi80749@aol.com [mailto:CDimi80749@aol.com]
Sent: Thursday, September 25, 2003 12:24 PM
To: Booth, Bradley; stds-802-3-10gbt@ieee.org
Subject: Re: [10GBASE-T] Proposed modification to PAR scope
Stuart,
In response to your comment, and mostly for the benefit of those
untrained in
the art of cabling,
I'll attempt to clarify the points in the discussion by providing
information
on the ISO nomenclature
to help reach closure on the cabling language used in the objectives.
1. ISO/IEC 11801 specifies horizontal cabling and backbone cabling
(i.e.,
topology).
2. ISO/IEC 11801 specifies both balanced cabling (copper) and optical
fibre
cabling (i.e., media).
------For balanced cabling, the performance specifications are
separated
into six classes (A to F)
------For Class D, E and F balanced components are defined in terms of
their
category.
------The category of component provides the Class of balanced cabling
performance.
+++++e.g., Category 6 components provide Class E balanced cabling
performance
3. ISO/IEC specifies transmission performance (topology) of the cabling
in
terms of the Channel (and permanent link).
To address each cabling attribute in a single objective we would need
to
describe each and then
select an ordering of the attributes to generate the objective.
e.g.,
+++Horizontal (topology)
+++Balanced (media)
+++Class/Category (transmission performance specifications)
+++Channel (transmission performance topology).
The resultant objective would read:
10GBASE-T Cabling: ====== Horizontal Balanced Class (D,E,F) Channel
At this point, I do not advocate modifying the objectives. I offer this
to
clarify
the points of discussion concerning the applicability of the usage of
horizontal cabling for
data center topologies.
Regards,
Chris
In a message dated 9/25/03 11:02:10 AM Eastern Daylight Time,
bradley.booth@intel.com writes:
<< This is being forward on Stuart's behalf as his restrictive notice
caused the email to be bounced. Thanks, Brad
------------------------------------------------------------------------
------------------------------------------------------------------------
-----------------------
Dear all,
Neither the TIA - where horizontal cabling extends from the
cross-connect to the TO - nor ISO/IEC - where horizontal cabling
subsystem is the equivalent - appears to be correct.
Is it not the "horizontal balanced cabling channel" or the "balanced
cabling horizontal channel"?
Regards
SJReeves
Stuart J. Reeves
Technical Manager
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-----Original Message-----
From: owner-stds-802-3-10gbt@majordomo.ieee.org
[mailto:owner-stds-802-3-10gbt@majordomo.ieee.org] On Behalf Of Cobb,
Terry R (Terry)
Sent: Thursday, September 25, 2003 9:06 AM
To: stds-802-3-10gbt@ieee.org
Subject: RE: [10GBASE-T] Proposed modification to PAR scope
The term ISO uses is "Balance Cabling" (Clause 6 of 11801, 2002)
and TIA uses "Horizontal Cabling", which is used in the Data Center
document to identify the cabling. I have been reminded often by others
that we should use ISO designations.
Terry
-----Original Message-----
From: pat_thaler@agilent.com
[mailto:pat_thaler@agilent.com]
Sent: Wednesday, September 24, 2003 6:26 PM
To: gzimmerman@solarflare.com; dan.dove@hp.com;
btolley@cisco.com; bradley.booth@intel.com; stds-802-3-10gbt@ieee.org
Subject: RE: [10GBASE-T] Proposed modification to PAR
scope
I agree that "on horizontal structured cabling" probably
needs a tweak. It could possibly be interpreted as requiring 100 m
operation for all supported media. As Terry points out, it doesn't
really reflect the data center as a focus of broad market potential.
Regards,
Pat
-----Original Message-----
From: George Zimmerman
[mailto:gzimmerman@solarflare.com]
Sent: Wednesday, September 24, 2003 3:42 PM
To: THALER,PAT (A-Roseville,ex1);
dan.dove@hp.com; btolley@cisco.com; bradley.booth@intel.com;
stds-802-3-10gbt@ieee.org
Subject: RE: [10GBASE-T] Proposed modification
to PAR scope
Pat - thanks for the clarifications - I'd missed
the fact that speed wasn't mentioned (must be still suffering from
Italian jet-lag). Scopes should be broad but clear. The CX4 scope is
probably a good model. "based on" is different than saying it must
implement it. (under this scope a 10GBASE-CX4 could incorporate other
line codes, etc.) Similarly "working over the wiring types used in
structured cabling" is a bit different than the text as written, which
enters into a more specific description of "structured cabling" (we had
a little discussion in Italy where some had a very narrow understanding
of what that means).
I'll have to think a little about an
alternative, but I think we're on the same principle: speed & wiring
types define 10GBASE-T, but the detailed description is for the
objectives.
George Zimmerman
gzimmerman@solarflare.com
tel: (949) 581-6830 ext. 2500
cell: (310) 920-3860
-----Original Message-----
From: pat_thaler@agilent.com
[mailto:pat_thaler@agilent.com]
Sent: Wednesday, September 24, 2003 3:28 PM
To: George Zimmerman; dan.dove@hp.com;
btolley@cisco.com; bradley.booth@intel.com; stds-802-3-10gbt@ieee.org
Subject: RE: [10GBASE-T] Proposed modification
to PAR scope
George,
I think Dan's suggestion went too far - very
specific media descriptions (like references to 11801) have always been
for the objectives rather then the PAR. On the other hand, the existing
scope is much more broad than previous projects:
Current scope:
The scope of this project is to specify
additions to and appropriate modifications of IEEE Std 802.3 (including
all approved amendments and corrigenda) to add a copper Physical Layer
(PHY) specification.
Howard's suggested scope:
Specify a Physical Layer (PHY) for operation at
10 Gb/s
on horizontal structured copper cabling,
using the existing
Media Access Controller, and with extensions
to the appropriate
physical layer management parameters, of IEEE
Std 802.3
CX4 scope:
The scope of this project is to specify
additions to and appropriate modifications of IEEE Std 802.3 as amended
by IEEE Std 802.3ae-2002 (and any other approved amendment or
corrigendum) to add a copper Physical Medium Dependent (PMD) option for
10 Gb/s operation, building upon the existing 10GBASE-X Physical
Coding Sublayer (PCS) and 10 Gigabit Attachment Unit Interface (XAUI)
specifications.
The CX4 scope text is much more similar to
Howard's suggested scope. Both have a statement about the speed. I
can't
recall any scope statement we have done for a PHY project that omitted
mention of speed. The CX4 scope doesn't say anything about the type of
copper, but it specifies that the PHY will be based on the X PCS and
the
XAUI specs which limits it pretty clearly. For 10GBASE-T, the intent to
work over the wiring types used in structured cabling and the 10 Gbit/s
speed are the defining factors.
Look at it this way. IEEE Std 802.3 already has
many copper Physical Layer specifications. Therefore the job listed in
the current scope statement has already been done. If the PAR is
approved with the current scope, the scope will be published by the
IEEE. How would a reader seeing that scope know what the project was
about and whether they were interested? Howard's scope is a more clear
statement of what we want to do.
If something in Howard's scope is too confining,
then please propose an alternative that is reasonably descriptive of
the
particular nature of this project - not something that could describe 5
or more other projects we have already done.
Regards,
Pat