Subject: [eman] eman requirements: "max/average" to "typical"

From: Juergen Quittek <[email-masked]>
Date: Thu, 27 Sep 2012 12:17:22 +0000

Dear all,

Here is an issue from discussing received comments on the eman
requirements:

The current version asks for means for reporting maximum and average power
for each power state.  The comment raised the point that these may not be
well defined.  Mouli and I discussed this and came up with the following
proposal:

OLD
   5.4.6.  Maximum and average power per Power State
 
   The standard must provide means for retrieving the maximum power and
   the average power for each supported Power State.  These values may
   be static.

NEW

   5.4.6.  Typical power per Power State

   The standard must provide means for retrieving the typical power for
   each supported Power State.

The assumption is that a "typical" power meets more the requirements by
an energy management system and would be more useful than a not well
defined "average" value.

Please give us your opinions on this proposal.

Thanks,
    Juergen

---

From: "John Parello (jparello)" <[email-masked]>
Date: Thu, 27 Sep 2012 17:14:05 +0000

HI Juergen,

Thanks. I agree that typical is more useful than average but you  threw out max. 

In our implementations each power state has a maximum value that the device will use for that state. Typical  and average is too lose a term for management.

If I have three power states say low, medium, high and the device reports typical power as 10,20, and 30W. I have no way of knowing that if I set the device to low it will not exceed the 10W and run at  30W.

We implemented the Max to allow device vendors to give specifics so that the mgt stations can have a hope of controlling the aggregate power. If you loosen the requirement to typical you effectively have no predictable control. 

Having Max is also in line with the way PoE states are communicated where depending on which PoE spec you implement you give 3 or 5 states and give the maximum at each state.

So yes on typical over average but you must have  max as well.

Jp

-----Original Message-----
From: [email-masked] [mailto:[email-masked]] On Behalf Of Juergen Quittek
Sent: Thursday, September 27, 2012 5:17 AM
To: eman mailing list
Subject: [eman] eman requirements: "max/average" to "typical"

Dear all,

The current version asks for means for reporting maximum and average power for each power state.  The comment raised the point that these may not be well defined.  Mouli and I discussed this and came up with the following
proposal:

OLD

NEW

The assumption is that a "typical" power meets more the requirements by an energy management system and would be more useful than a not well defined "average" value.

Thanks,
    Juergen

_______________________________________________
eman mailing list
[email-masked]
https://www.ietf.org/mailman/listinfo/eman

---

From: Juergen Quittek <[email-masked]>
Date: Thu, 27 Sep 2012 18:45:14 +0000

Hi John,

Thank you for your comment.  This would look like

OLD

NEW
   5.4.6. Maximum and typical power per Power State

   The standard must provide means for retrieving the maximum power and
   the typical power for each supported Power State.

I don't think we need the sentence on values being static.

Who would have a problem with this version?

Thanks,
    Juergen

On 27.09.12 19:14, "John Parello (jparello)" <[email-masked]> wrote:

>In our implementations each power state has a maximum value that the
>device will use for that state. Typical  and average is too lose a term
>for management.
>
>If I have three power states say low, medium, high and the device reports
>typical power as 10,20, and 30W. I have no way of knowing that if I set
>the device to low it will not exceed the 10W and run at  30W.
>
>We implemented the Max to allow device vendors to give specifics so that
>the mgt stations can have a hope of controlling the aggregate power. If
>you loosen the requirement to typical you effectively have no predictable
>control. 
>
>Having Max is also in line with the way PoE states are communicated where
>depending on which PoE spec you implement you give 3 or 5 states and give
>the maximum at each state.
>
>The current version asks for means for reporting maximum and average
>power for each power state.  The comment raised the point that these may
>not be well defined.  Mouli and I discussed this and came up with the
>following
>proposal:
>
>OLD