Content-Type: multipart/alternative;
 boundary=Apple-Mail-3FBFAA62-A1C0-4BEE-B56D-7FF103CAE019
Content-Transfer-Encoding: 7bit
From: Carlos Pignataro <cpignata@gmail.com>
Mime-Version: 1.0 (1.0)
Date: Fri, 8 May 2026 11:08:54 +0200
Message-Id: <8876B117-7E24-476A-99AA-A8EFD1140EFB@gmail.com>
References: <CC0D8A2E-8992-43FD-8604-E804C9F3780E@tony.li>
In-Reply-To: <CC0D8A2E-8992-43FD-8604-E804C9F3780E@tony.li>
To: Tony Li <tony.li@tony.li>
Message-ID-Hash: M2ZF6JEL5MGYWZ77FCLDUHO65ZN7YPFI
CC: Christian Hopps <chopps@chopps.org>, lsr <lsr@ietf.org>, lsr-ads@ietf.org,
 ops-ads <ops-ads@ietf.org>, green@ietf.org
Precedence: list
Subject: =?utf-8?q?=5BGreen=5D_Re=3A_Next_steps_for_draft-many-lsr-power-group-02?=
Archived-At: 
 <https://mailarchive.ietf.org/arch/msg/green/1fS3CnGCOPaj3wpHsX_g6oxFQpc>


--Apple-Mail-3FBFAA62-A1C0-4BEE-B56D-7FF103CAE019
Content-Type: text/plain;
	charset=utf-8
Content-Transfer-Encoding: quoted-printable

Hi, Tony,

Thanks for your response =E2=80=94 it is still orthogonal to my question.=20=


I=E2=80=99m asking for a methodology / framework question =E2=80=94 not a sc=
enario-dependent quantifiable ooutcome one.=20

I=E2=80=99m not asking =E2=80=9Cwill this always save energy and how much?=E2=
=80=9D  I=E2=80=99m asking =E2=80=9Chow is the mechanism evaluated rigorousl=
y?=E2=80=9D =20

IOW, I=E2=80=99m asking for an evaluation model to be discussed and included=
 =E2=80=94 not an operational conclusion. A =E2=80=9Chow=E2=80=9D, not a num=
ber.=20

My concern is that you are evaluating gross savings. And I am suggesting we c=
are more about net savings. And eval mechanism ought to account for both: =20=

* the energy savings enabled by consolidation/idling, and=20
* the incremental energy cost introduced by the mechanism itself.

It=E2=80=99s a methodology question =E2=80=94 not a quantity or even simulat=
ion output one.=20

Thumb typed by Carlos Pignataro.
Excuze typofraphicak errows

> On May 5, 2026, at 20:20, Tony Li <tony.li@tony.li> wrote:
>=20
> =EF=BB=BF
> Hi Carlos,
>=20
>> The intent is simply to ensure that the evaluation captures the net syste=
m-level impact (i.e., whether the mechanisms enable sufficient consolidation=
 to reduce overall energy consumption relative to a baseline.) In other word=
s, the considering both sides: the additional overhead introduced, and the p=
otential energy savings from traffic consolidation and resource idling. How i=
s the simulation / premise / framework evaluating net >0 or <0?
>=20
>=20
> Thank you for the clarification, but I still cannot answer.  It depends.
>=20
> If the network is running at 98% of capacity throughout, then there is not=
hing that can be done.  No savings, so no benefit.
>=20
> If the network is running at 10% of capacity, then it=E2=80=99s very likel=
y that 70-80% of the network can be shut down (depending on the operator's r=
edundancy requirements),
>=20
> What we have seen is that our simulations have shown excellent benefits, b=
ut the exact number vary greatly, again depending on the traffic demand, top=
ology, hardware, etc.
>=20
> I get that you want an easy answer.  I=E2=80=99m sorry to say that as with=
 many things in life, there is none.
>=20
> This technology will help networks that have substantial variance in their=
 traffic demand, and not at all with networks that run continually saturated=
.  And in between, it will give some benefit, but your mileage may vary. Whe=
ther it=E2=80=99s enough to matter depends on your personal situation and th=
e price of power.
>=20
> Tony
>=20

--Apple-Mail-3FBFAA62-A1C0-4BEE-B56D-7FF103CAE019
Content-Type: text/html;
	charset=utf-8
Content-Transfer-Encoding: quoted-printable

<html class=3D"apple-mail-supports-explicit-dark-mode"><head><meta http-equi=
v=3D"content-type" content=3D"text/html; charset=3Dutf-8"></head><body dir=3D=
"auto">Hi, Tony,<div><br></div><div>Thanks for your response =E2=80=94 it is=
 still orthogonal to my question.&nbsp;</div><div><br></div><div>I=E2=80=99m=
 asking for a methodology / framework question =E2=80=94 not a scenario-depe=
ndent quantifiable ooutcome one.&nbsp;</div><div><br></div><div>I=E2=80=99m n=
ot asking =E2=80=9Cwill this always save energy and how much?=E2=80=9D &nbsp=
;I=E2=80=99m asking =E2=80=9Chow is the mechanism evaluated rigorously?=E2=80=
=9D &nbsp;</div><div><br></div><div>IOW, I=E2=80=99m asking for an evaluatio=
n model to be discussed and included =E2=80=94 not an operational conclusion=
. A =E2=80=9Chow=E2=80=9D, not a number.&nbsp;</div><div><br></div><div>My c=
oncern is that you are evaluating <b>gross savings</b>. And I am suggesting w=
e care more about <b>net savings</b>. And eval mechanism ought to account fo=
r both: &nbsp;</div><div>* the energy savings enabled by consolidation/idlin=
g, and&nbsp;</div><div>* the incremental energy cost introduced by the mecha=
nism itself.</div><div><br></div><div>It=E2=80=99s a methodology question =E2=
=80=94 not a quantity or even simulation output one.&nbsp;</div><div><br id=3D=
"lineBreakAtBeginningOfSignature"><div dir=3D"ltr"><span class=3D"Apple-styl=
e-span" style=3D"-webkit-tap-highlight-color: rgba(26, 26, 26, 0.298);">Thum=
b typed by Carlos Pignataro.</span><div><span class=3D"Apple-style-span" sty=
le=3D"-webkit-tap-highlight-color: rgba(26, 26, 26, 0.296875); -webkit-compo=
sition-fill-color: rgba(175, 192, 227, 0.230469); -webkit-composition-frame-=
color: rgba(77, 128, 180, 0.230469); ">Excuze typofraphicak errows</span></d=
iv></div><div dir=3D"ltr"><br><blockquote type=3D"cite">On May 5, 2026, at 2=
0:20, Tony Li &lt;tony.li@tony.li&gt; wrote:<br><br></blockquote></div><bloc=
kquote type=3D"cite"><div dir=3D"ltr">=EF=BB=BF<span></span><br><span>Hi Car=
los,</span><br><span></span><br><blockquote type=3D"cite"><span>The intent i=
s simply to ensure that the evaluation captures the net system-level impact (=
i.e., whether the mechanisms enable sufficient consolidation to reduce overa=
ll energy consumption relative to a baseline.) In other words, the consideri=
ng both sides: the additional overhead introduced, and the potential energy s=
avings from traffic consolidation and resource idling. How is the simulation=
 / premise / framework evaluating net &gt;0 or &lt;0?</span><br></blockquote=
><span></span><br><span></span><br><span>Thank you for the clarification, bu=
t I still cannot answer. &nbsp;It depends.</span><br><span></span><br><span>=
If the network is running at 98% of capacity throughout, then there is nothi=
ng that can be done. &nbsp;No savings, so no benefit.</span><br><span></span=
><br><span>If the network is running at 10% of capacity, then it=E2=80=99s v=
ery likely that 70-80% of the network can be shut down (depending on the ope=
rator's redundancy requirements),</span><br><span></span><br><span>What we h=
ave seen is that our simulations have shown excellent benefits, but the exac=
t number vary greatly, again depending on the traffic demand, topology, hard=
ware, etc.</span><br><span></span><br><span>I get that you want an easy answ=
er. &nbsp;I=E2=80=99m sorry to say that as with many things in life, there i=
s none.</span><br><span></span><br><span>This technology will help networks t=
hat have substantial variance in their traffic demand, and not at all with n=
etworks that run continually saturated. &nbsp;And in between, it will give s=
ome benefit, but your mileage may vary. Whether it=E2=80=99s enough to matte=
r depends on your personal situation and the price of power.</span><br><span=
></span><br><span>Tony</span><br><span></span><br></div></blockquote></div><=
/body></html>=

--Apple-Mail-3FBFAA62-A1C0-4BEE-B56D-7FF103CAE019--