Re: [802.3_10SPE] Proposed response to MDI connector comment r02-14

[Yong Kim <yongkim.mail@xxxxxxxxx>]

WRT to call for multiple connectors versus defining the MDI (one, not multiple) connectors,

before looking at 802.3 tradition and mandate for MDI (this is the effect of), we should look at the rationale(root cause), and some examples that directly benefited the world.

Why do we do standards first place?   <=== Multi-vendor, open, interoperability.

Why has IEEE 802.3 been so successful?  <=== In part, due to actually delivering industry-wide interoperability by not compromising (well.. hardly ever) things that effect interoperability.

So What's with MDI?

When interoperable systems connect, it should work together.

If it does not, you could test for interoperable metrics at the MDI -- the exposed, medium dependent, interoperability (electrical/optical, functional, detectable behavior, mechanical, etc, that that is required to assure) test point.  

If we define MDI, it is up to us to put all normative requirements to assure -- this is the whole point of doing std.

Aside from the backplane Ethernet, chip-to-module, and 100Mbps (and possibly 1Gbps) unshielded one-pair -- all justifying various degree of unspecifiable connection mechanisms, all Ethernet that had clear need for a connector always had an MDI.  Why?  Interoperability ==> why we have standards.

Over the years, people argued that an alternate MDI is just as good.  That's fine.  So long as we have THE MDI spec to reference and compare to.  You want to run 100BASE-TX on star-quad on pairs 3-4, and 5-6 or RJ45-like connector?   Fine -- your own engineering issue, and only you'll have to compare its performance to THE MDI reference. Most likely, that's what you are doing -- comparing measurements of the alternate medium/connector to THE MDI spec.

So I am not stating my preferences for a fewer connectors.  I am (re-)stating the reason to have the MDI spec.   If this group decides to list several connectors as references, don't call any of them MDI or MDI connector.   They are factually not.

best regards,

Yong Kim, affiliation: NIO

On Fri, Aug 16, 2019 at 11:53 AM Bruce Nordman <bnordman@xxxxxxx> wrote:

I don't have sufficient background in 802.3 to know what is allowable/usual for connectors, but from an application perspective, I do see the potential for more than one connector type.  Others have noted that specific application contexts like automotive and industrial may have special needs for vibration, moisture exclusion, etc.  For buildings, I expect there to be some SPE connections which are made essentially just once during construction or retrofit and then hidden in walls, boxes, or plenums, whereas others might be exposed to users and used frequently in the same way that USB connectors are.

We do have multiple connector types for 115V AC - the typical outlet plug, plus the flatter NEMA plug that used to be commonly seed on the back of desktop PCs. 

Fewer connector types is always better, and deep thinking/consideration is clearly needed, but for SPE I don't know that the right answer is necessarily only one.  I would agree that for a given large application context, there should be just one.

Thanks,

--Bruce

On Fri, Aug 16, 2019 at 11:14 AM Christopher T. Diminico <00000025925d7602-dmarc-request@xxxxxxxx> wrote:

Yong, 

Further, for reference, SPE MDIs. 

•        802.3bw (Standard) 100BASE-T1 (100 Mb/s) - MDI connector

-        The mechanical interface to the balanced cabling is a 2-pin connector or 2 pins of a multi-pin connector.

•        802.3bp (Standard) 1000BASE-T1 (1000 Mb/s) - MDI connector type A and type B

-        The mechanical interface to the balanced cabling is a 2-pin connector or 2 pins of a multi-pin connector.

•        802.3ch (draft) 2.5/5/10GBASE-T1 - MDI connector

•        The mechanical interface to the shielded balanced cabling is a 2-pin connector with a shield. Further specification of the mechanical interface is beyond the scope of this standard.

•        802.3cg (draft) 10BASE-T1L and 10BASE-Ts (10 Mb/s) – MDI jack connector and plug

-        IEC 63171-1 or IEC 63171-6 connectors may be used; plug connector on cabling and MDI jack connector on the PHY. 

Considering network topology, Single pair Ethernet is  poised to enable a new class of low power Ethernet devices that will facilitate networking and powering the billions of end point sensors forecast by the year 2022

.

Regards, Chris

 

-----Original Message-----
From: Christopher T. Diminico <cdimi80749@xxxxxxx>
To: yongkim.mail <yongkim.mail@xxxxxxxxx>; STDS-802-3-10SPE <STDS-802-3-10SPE@xxxxxxxxxxxxxxxxx>
Sent: Fri, Aug 16, 2019 11:13 am
Subject: Re: [802.3_10SPE] Proposed response to MDI connector comment r02-14

Yong, 

To aid in the discussion, please see IEEE Std 802.3-2018, IEEE Standard for Ethernet section one MDI definition (1.4.324 Medium Dependent Interface (MDI)) and compatibility interfaces (1.1.3.2 Compatibility interfaces) defined including MDI ((a) Medium Dependent Interfaces (MDI)). 

Regards, Chris

1.4.324 Medium Dependent Interface (MDI): The mechanical and electrical or optical interface between

the transmission medium and the MAU (e.g., 10BASE-T) or the PHY (e.g., 1000BASE-T) and also between

the transmission medium and any associated (optional per IEEE Std 802.3, Clause 33) Powered Device (PD)

or Endpoint Power Sourcing Equipment (PSE).

1.1.3.2 Compatibility interfaces

The following important compatibility interfaces are defined within what is architecturally the Physical

Layer.

a) Medium Dependent Interfaces (MDI). To communicate in a compatible manner, all stations shall

adhere rigidly to the exact specification of physical media signals defined in the appropriate clauses

in this standard, and to the procedures that define correct behavior of a station. The medium-independent

aspects of the LLC sublayer and the MAC sublayer should not be taken as detracting from

this point; communication in an Ethernet Local Area Network requires complete compatibility at the

Physical Medium interface (that is, the physical cable interface).

-----Original Message-----
From: Yong Kim <yongkim.mail@xxxxxxxxx>
To: STDS-802-3-10SPE <STDS-802-3-10SPE@xxxxxxxxxxxxxxxxx>
Sent: Thu, Aug 15, 2019 6:08 pm
Subject: Re: [802.3_10SPE] Proposed response to MDI connector comment r02-14

Hi CRG,

Despite my ressoable efforts to stand firm on the use of the traditional and formal definition of MDI that MDI is a mandatory interoperability interface - functional, mechanical, etc., this response uses MDI to mean informative referenced mechanical connector.   So I'll submit a disapprove comment on this aspect of this response, should the sponsor ballot goes through another recalculation.

best regards,

Yong Kim, affiliation: NIO

On Wed, Aug 14, 2019 at 4:12 PM George Zimmerman <george@xxxxxxxxxxxxxxxxxxxx> wrote:

Thank you all for a productive day.  Tomorrow we start at 8am (please begin arriving at 7:15), to formally close this comment as well as the remaining state diagram and new late comments.
Please review this response (approved per motion 5) overnight and email me any necessary corrections.
-george

----
PROPOSED ACCEPT IN PRINCIPLE.
---
add Annex A (Bibliography) into the draft, with the editing instruction:

Insert the following references and associated editor's notes in alphanumeric order as follows:

Editor's Note (to be removed prior to publication):
IEC 63171-1 is in the FDIS stage. The publication date for IEC 63171-1 will need to be inserted prior to publication of IEEE Std 802.3cg.

IEC 63171-1 Ed.1:201x, Connectors for Electrical and Electronic Equipment -
Part 1: Detail specification for 2-way, shielded or unshielded, free and fixed connectors: mechanical mating information, pin assignment and additional requirements for type 1 / Copper LC Style

Editor's Note (to be removed prior to publication):
IEC 63171-6 is in the FDIS stage. The publication date for IEC 63171-6 will need to be inserted prior to publication of IEEE Std 802.3cg.

IEC 63171-6 Ed.1:201x Connectors for Electrical and Electronic Equipment -
Detail specification for 2-way and 4-way (data/power), shielded, free and fixed connectors for power and data transmission with frequencies up to 600 MHz
---

146.8.1 MDI connectors -Page 171, Line 52 add new paragraph;
Connectors meeting the mechanical requirements of IEC 63171-1 or IEC 63171-6 may be used as the mechanical interface to the balanced cabling. The plug connector is used on the balanced cabling and the MDI jack connector on the PHY. The IEC 63171-1 plug and jack are depicted (for informational use only) in Figure 146-29 and Figure 146-30 respectively, and the mating interface is depicted in Figure 146-31. The IEC 63171-6 plug and jack are depicted (for informational use only) in Figure 146-32 and Figure 146-33 respectively, and the mating interface is depicted in Figure 146-34. These connectors should support link segment DCR characteristics for 1.02 mm (18 AWG) to 0.40 mm (26 AWG) in Table 146B-1.

Re-instate IEC 63171-1 plug and jack figures from D3.1 as Figures 146-29, 146-30, and 146-31.
Re-instate IEC 63171-6 plug and jack figures from D3.1 as Figures 146-31, 146-32, and 146-33.


147.9.1 MDI connectors -Page 220, Line 52 add new paragraph;
Connectors meeting the mechanical requirements of IEC 63171-1 or IEC 63171-6 may be used as the mechanical interface to the balanced cabling. The plug connector is used on the balanced cabling and the MDI jack connector on the PHY. The IEC 63171-1 plug and jack are depicted (for informational use only) in Figure 147-21 and Figure 147-22 respectively and the mating interface is depicted in Figure 147-23. The IEC 63171-6 plug and jack are depicted (for informational use only) in Figure 147-24 and Figure 147-25 respectively and the mating interface is depicted in Figure 147-26.  These connectors should support link segment DCR characteristics for 1.02 mm (18 AWG) to 0.40 mm (26 AWG) in Table 146B-1.

Re-instate IEC 63171-1 plug and jack figures from D3.1. as Figures 147-21, 147-22, and 147-23.
Re-instate IEC 63171-6 plug and jack figures from D3.1 as as Figures 147-24, 147-25, and 147-26.

Editorial license to revise figure numbers as needed.

Motion #5:
Move to respond to comment r02-14 with Alternative B: (see straw polls, ACCEPT IN PRINCIPLE - Same text as "A", but with -6 as well.  (Return to the draft 3.0 text, with references corrected))
M:  Chris Diminico
S:  Ron Nordin
(Technical >= 75%)
Y:13  N: 4 A: 7
Motion Passes

George A. Zimmerman, Ph.D.
President & Principal Consultant
CME Consulting, Inc.
Experts in PHYsical Layer Communications
1-310-920-3860
george@xxxxxxxxxxxxxxxxxxxx<mailto:george@xxxxxxxxxxxxxxxxxxxx>


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--

Bruce Nordman
Lawrence Berkeley National Laboratory
nordman.lbl.gov
BNordman@xxxxxxx
510-486-7089
m: 510-501-7943

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