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Re: [802.3_4PPOE] Type 4 PD



Yair - the text relating to simultaneously powering has been accepted for a while. I would not support changing it.

George A. Zimmerman, Ph.D.
CME Consulting, Inc.
Experts in PHYsical Layer Communications
310-920-3860


On Oct 22, 2017, at 1:57 AM, Yair Darshan <YDarshan@xxxxxxxxxxxxx> wrote:

Hi George,

In your proposed text:

“1.4.418aa Type 3 PD: A single-signature PD that requests Class 1 to Class 6, or a dual-signature PD that requests Class 1 to Class 4 on both Modes during Physical Layer classification.  Additionally, the PD implements Multiple-Event classification, and accepts power on both Modes simultaneously. (See IEEE 802.3, Clause 145).

 

1.4.418ac Type 4 PD: A single-signature PD that requests Class 7 or Class 8, or a dual-signature PD that request Class 5 on at least one Mode during Physical Layer classification.  Additionally,  the PD implements Multiple-Event classification, is capable of Data Link Layer classification, and accepts power on both Modes simultaneously. (See IEEE 802.3, Clause 145).”

The use of “simultaneously” is confusing. Some readers will interpret that you must turn both modes at exactly the same time which is definitely not the intent, especial for dual signature PDs.

I suggest the following to remove the word “simultaneously”.

We had the same issue in the draft (main body) in previous releases and we fix it in this way.

Yair

 

 

From: George Zimmerman [mailto:george@xxxxxxxxxxxxxxxxxxxx]
Sent: Friday, October 20, 2017 8:05 PM
To: STDS-802-3-4PPOE@xxxxxxxxxxxxxxxxx
Subject: Re: [802.3_4PPOE] Type 4 PD

 

EXTERNAL EMAIL

OK, so the path of various solutions has gotten convoluted, and Heath pointed out to me offline that we need to straighten out Lennart & Andrea’s different parts.  This combination seems to work:

 

1.4.418aa Type 3 PD: A single-signature PD that requests Class 1 to Class 6, or a dual-signature PD that requests Class 1 to Class 4 on both Modes during Physical Layer classification, implements

Multiple-Event classification, and accepts power on both Modes simultaneously. (See IEEE 802.3, Clause 145).

 

1.4.418ac Type 4 PD: A single-signature PD that requests Class 7 or
Class 8, or a dual-signature PD that request Class 5 on at least one
Mode during Physical Layer classification, implements Multiple-Event
classification, is capable of Data Link Layer classification, and
accepts power on both Modes simultaneously. (See IEEE 802.3, Clause
145).

 

One minor thing is that we can expect a comment on both of these that it reads like any single-sig class 1 to 6 (type 3,  or 8 for type 4) is a type 3,4 PD; while a dual-sig requires the additional features listed.  The English doesn’t parse uniquely like a logic equation.  What I was trying to wrap my head around was whether there was a reordering or rephrasing that made it clear that the logic was: ( (SS = class 7 + class 8) + (DS = maxclass 5) ) * (features).

 

Breaking these into two sentences might work:

1.4.418aa Type 3 PD: A single-signature PD that requests Class 1 to Class 6, or a dual-signature PD that requests Class 1 to Class 4 on both Modes during Physical Layer classification.  Additionally, the PD implements Multiple-Event classification, and accepts power on both Modes simultaneously. (See IEEE 802.3, Clause 145).

 

1.4.418ac Type 4 PD: A single-signature PD that requests Class 7 or Class 8, or a dual-signature PD that request Class 5 on at least one Mode during Physical Layer classification.  Additionally,  the PD implements Multiple-Event classification, is capable of Data Link Layer classification, and accepts power on both Modes simultaneously. (See IEEE 802.3, Clause 145).

 

From: George Zimmerman [mailto:george@xxxxxxxxxxxxxxxxxxxx]
Sent: Friday, October 20, 2017 8:55 AM
To: STDS-802-3-4PPOE@xxxxxxxxxxxxxxxxx
Subject: Re: [802.3_4PPOE] Type 4 PD

 

This does not fix the problem, because both type 3 and type 4 still include single-sig class 6.  Add to that, that this is trying to make the definition complex.

 

I suggest we stick to fixing the type 4 definition, and your suggestion below (on type 3) may provide the fix, but it isn’t readily apparent.

 

The problem is that dual-sig which classify as class 5 or 6 on a pairset are outside the type 4 definition.  We should focus on including those into type 4.

-george

 

 

 

 

From: Andrea Agnes [mailto:andrea.agnes181@xxxxxxxxx]
Sent: Friday, October 20, 2017 4:01 AM
To: STDS-802-3-4PPOE@xxxxxxxxxxxxxxxxx
Subject: Re: [802.3_4PPOE] Type 4 PD

 

ok I agree

but dual signature PD Class 5 would became both Type 3 and Type 4.

 

I suggest accordingly modification of Type 3 definition:

 

1.4.418aa Type 3 PD: A single-signature PD that requests Class 1 to Class 6, or a dual-signature PD that requests Class 1 to Class 4 on both Modes during Physical Layer classification, implements

Multiple-Event classification, and accepts power on both Modes simultaneously. (See IEEE 802.3, Clause 145).

 

 

 

2017-10-20 11:54 GMT+02:00 Lennart Yseboodt <lennartyseboodt@xxxxxxxxx>:

Hi Andrea,

That would make Class 5 and 6 single-signature PDs to be both Type 3
and Type 4.

Suggest:
1.4.418ac Type 4 PD: A single-signature PD that requests Class 7 or
Class 8, or a dual-signature PD that request Class 5 on at least one
Mode during Physical Layer classification, implements Multiple-Event
classification, is capable of Data Link Layer classification, and
accepts power on both Modes simultaneously. (See IEEE 802.3, Clause
145).

Not pretty,... but accurate.

Lennart


On Fri, 2017-10-20 at 11:50 +0200, Andrea Agnes wrote:
> The definition of type 4 is:
>
> 1.4.418ac Type 4 PD: A PD that requests Class 7 or Class 8 during
> Physical Layer classification, implements Multiple-Event
> classification, is capable of Data Link Layer classification, and
> accepts power on both Modes simultaneously. (See IEEE 802.3, Clause
> 145).
>
> That definition doesn't include Dual signature PDs because the
> Physical Layer classification is limited to Class 5. 
>
> REMEDY : Changing the definition to:
> 1.4.418ac Type 4 PD: A PD that requests Class 5 or higher during
> Physical Layer classification, implementsMultiple-Event
> classification, is capable of Data Link Layer classification, and
> accepts power on both Modes simultaneously. (See IEEE 802.3, Clause
> 145).
>
> Proposed remedy is an extention of Type 4 PD, limited to Class 5 and
> Class 6 single signature only if PD is capable of Data Link Layer
> classification.
>
> Comments?
>
> I check if there are limits related to the Type and not to the Class
> value.
>
> Thanks
> Regards
> Andrea