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Re: [802.3_4PPOE] Definition of alt_pwrd_pri



Jean - what would you suggest?
Remember, our job is not to capture the ‘initial purpose’ but to describe the behavior.  An abstract ‘decision’ is only observable by the resulting actions, but these shouldn’t be future actions.   in this case, according to the agreed part of the definition, the action is activating the circuitry that controls the operating voltage.

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


On Oct 23, 2017, at 3:39 PM, Picard, Jean <000009cdbf000550-dmarc-request@xxxxxxxx> wrote:

I don’t agree with this.

The initial purpose of alt_pwr_pri/sec was to indicate that the PSE has decided to power the pri/sec but has not necessarily started yet, meaning it may not have started to corrupt the detection/class of the other alternate.

See below from CLASS_EVAL_PRI block

 

 

<image004.png>

 

 

Regards

 

Jean Picard

 

 

From: Yair Darshan [mailto:YDarshan@xxxxxxxxxxxxx]
Sent: Thursday, October 19, 2017 3:14 PM
To: STDS-802-3-4PPOE@xxxxxxxxxxxxxxxxx
Subject: [EXTERNAL] Re: [802.3_4PPOE] Definition of alt_pwrd_pri

 

Looks good now.

Yair

 

From: Lennart Yseboodt [mailto:lennartyseboodt@xxxxxxxxx]
Sent: Thursday, October 19, 2017 10:10 PM
To: Yair Darshan <YDarshan@xxxxxxxxxxxxx>; STDS-802-3-4PPOE@xxxxxxxxxxxxxxxxx
Subject: Re: [802.3_4PPOE] Definition of alt_pwrd_pri

 

EXTERNAL EMAIL

OK, good, so we do need circuitry.

 

Thus it becomes:

 

FALSE:  The circuitry that applies operating voltage to the Primary alternative is disabled.

TRUE: The circuitry that applies operating voltage to the Secondary alternative is enabled.

 

Lennart

 

 

On Thu, 2017-10-19 at 18:56 +0000, Yair Darshan wrote:

Correct.

Yair.

 

From: George Zimmerman [mailto:george@xxxxxxxxxxxxxxxxxxxx]
Sent: Thursday, October 19, 2017 9:19 PM
To: STDS-802-3-4PPOE@xxxxxxxxxxxxxxxxx
Subject: Re: [802.3_4PPOE] Definition of alt_pwrd_pri

 

EXTERNAL EMAIL

I kept the word circuitry in there, because it is already referenced in the definition. I could live with your suggestion, but I recall (maybe incorrectly) that the reason that the statement was in terms of enabling or disabling the circuitry was to make it clear that the variable is TRUE in the inrush state where the voltage is ramping up and may not quite be established.

 

From: Lennart Yseboodt [mailto:lennartyseboodt@xxxxxxxxx]
Sent: Thursday, October 19, 2017 11:11 AM
To: STDS-802-3-4PPOE@xxxxxxxxxxxxxxxxx
Subject: Re: [802.3_4PPOE] Definition of alt_pwrd_pri

 

Hi George, Chad,

 

I am in favor of this. It is descriptive and does not venture in either the past or the future.

 

There are a couple of PoDL subtleties in there that we might be able to drop though:

 

FALSE: The PSE applies operating voltage to the primary Alternative

TRUE: The PSE does not apply operating voltage to the primary Alternative.

 

Did I delete anything we need to keep ?

 

Lennart

 

 

On Thu, 2017-10-19 at 17:34 +0000, Chad Jones (cmjones) wrote:

I think George has hit on something here. Let’s discuss this solution:

 

alt_pwrd_pri

A variable that controls the circuitry that the PSE uses to power the PD over the Alternative that has been assigned as Primary.

Values:

FALSE: The circuitry that applies full operating voltage to the Primary alternative of the PI is disabled.

TRUE: The circuitry that applies full operating voltage to the Primary alternative of the PI is enabled.

 

alt_pwrd_sec

A variable that controls the circuitry that the PSE uses to power the PD over the Alternative that has been assigned as Secondary.

Values:

FALSE: The circuitry that applies full operating voltage to the Secondary alternative of the PI is disabled.

TRUE: The circuitry that applies full operating voltage to the Secondary alternative of the PI is enabled.

 

 

Are there holes in this solution?

 

Chad Jones

Tech Lead, Cisco Systems

Chair, IEEE P802.3bt 4PPoE Task Force

Principal, NFPA 70 CMP3

 

From: Yair Darshan <YDarshan@xxxxxxxxxxxxx>
Reply-To: Yair Darshan <YDarshan@xxxxxxxxxxxxx>
Date: Thursday, October 19, 2017 at 12:56 PM
To: 4PPOE Reflector <STDS-802-3-4PPOE@xxxxxxxxxxxxxxxxx>
Subject: Re: [802.3_4PPOE] Definition of alt_pwrd_pri

 

Hi Lennart,

I understand the principle you want to follow. Please note that the additional description in the TRUE case of detection and classification was added due to the importance of not power unless these action where done while in the FALSE case obviously they are not required.

Logically there is no reason to make the changes you propose.

The question is now if to have for that matter short description or clear description. In this case I preffer clear description i.e. keep it as is but to clean the “will” issue.

Yair

 

From: Lennart Yseboodt [mailto:lennartyseboodt@xxxxxxxxx]
Sent: Thursday, October 19, 2017 10:27 AM
To: STDS-802-3-4PPOE@xxxxxxxxxxxxxxxxx
Subject: [802.3_4PPOE] Definition of alt_pwrd_pri

 

EXTERNAL EMAIL

Hi all,

 

<image001.png>

 

We discussed this at the last meeting and I feel we did not end up with a good solution.

 

The definition of variables should be restricted to what the variable does or represents.

These variables' "TRUE" description includes behaviour that (should have) happened in the past, as well as making a forward looking statement.

 

If we look at how these variables are actually used, the definition really is very simple:

 

FALSE = The PSE is not to apply power to the XYZ Alternative.

TRUE = The PSE is to apply power to the XYZ Alternative.

 

Objections ?

 

Lennart

PNG image

PNG image