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RE: [10GBASE-T] Proposed modification to PAR scope

From Chris Di Minico...

-----Original Message-----
From: [] 
Sent: Thursday, September 25, 2003 12:24 PM
To: Booth, Bradley;
Subject: Re: [10GBASE-T] Proposed modification to PAR scope


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
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

2. ISO/IEC 11801 specifies both balanced cabling (copper) and optical
cabling (i.e., media).
------For balanced cabling,  the performance specifications are
into six classes (A to F) 
------For Class D, E and F balanced components are defined in terms of
------The category of component provides the Class of balanced cabling 
+++++e.g., Category 6 components provide Class E balanced cabling

3. ISO/IEC specifies transmission performance (topology) of the cabling
terms of the Channel (and permanent link).

 To address each cabling attribute in a single objective we would need
describe each and then 
select an ordering of the attributes to generate the objective. 
+++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
the points of discussion concerning the applicability of the usage of 
horizontal cabling for 
data center topologies. 



In a message dated 9/25/03 11:02:10 AM Eastern Daylight Time, 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"?
 Stuart J. Reeves
 Technical Manager 
 KRONE UK celebrating 25 Years of making the right connections 
 KRONE (UK) Technique Limited
 Runnings Road
 Kingsditch Trading Estate
 GL51 9NQ
 Email: <
 <>  <
 <> > >
 Tel: +44 (0)1242 264 471
 Fax: +44 (0)1242 264 652
 Mobile: +44 (0)7768 463 265 
    -----Original Message-----
 [] On Behalf Of Cobb,
 Terry R (Terry)
    Sent: Thursday, September 25, 2003 9:06 AM
    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.
        -----Original Message-----
        Sent: Wednesday, September 24, 2003 6:26 PM
        Subject: RE: [10GBASE-T] Proposed modification to PAR
        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.
            -----Original Message-----
            From: George Zimmerman
            Sent: Wednesday, September 24, 2003 3:42 PM
            To: THALER,PAT (A-Roseville,ex1);;;;
            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
            George Zimmerman
            tel: (949) 581-6830 ext. 2500
            cell: (310) 920-3860
            -----Original Message-----
            Sent: Wednesday, September 24, 2003 3:28 PM
            To: George Zimmerman;;;;
            Subject: RE: [10GBASE-T] Proposed modification
 to PAR scope
            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)
            The CX4 scope text is much more similar to
 Howard's suggested scope. Both have a statement about the speed. I
 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
 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
 particular nature of this project - not something that could describe 5
 or more other projects we have already done.