[irtf-discuss] Re: [Green] Re: Re: Network Equipment Energy Efficiency Metric

[Toerless Eckert <[e-mail]>]

Thanks, Dean

Some thoughts:

1. It is always helpful to  mention the name of a draft discussed in the email. Ideally even in the subject line so that searches on the mail archive and data-tracker find the info discussed.

2. The draft might need to refer to some BMWG definition of those percentages. aNDR if
i remember correctly (aggregate non-drop rate).

3. It might be useful to ask for a maximum power consumption power value and capture
an explanation of the condition under which it happens if it is higher than the 100%
load power consumption.

For example, on devices that use CPU for forwarding, the control plane may consume 
significant amount of power durign reconvergence events, when e.g.: multicore
parallelized BGP (in good products ;-) tries to reconverge. Or
during bootstrap when all linecards are initialized or the like.

Cheers
    Toerless

On Tue, Nov 12, 2024 at 09:06:57AM +0000, Dean Bogdanovic wrote:
> In the draft presented, we are taking different loads into the account
> 
> Idle State (0 bps): When the device is powered on but not forwarding
>    any data.
> 
>    Low Utilization: A percentage (15%) of the device's maximum
>    forwarding capacity.
> 
>    Medium Utilization: 50% of maximum capacity.
> 
>    High Utilization: Near the device's maximum forwarding capacity
>    (90%).
> 
> The whole point of testing to see how the performance is related to energy
> consumption in standardized conditions. If STC can’t be established, the
> testing conditions (temp, relative humidity, atmospheric pressure) should be
> reported.
> 
> Also, we are not looking to report what energy source the network operator
> is using. This up to them to figure it out. We don’t have the expertise in
> energy transmission and trying to figure out what energy source to use based
> on certain conditions.
> 
> Dean
> 
> On 12 Nov 2024, at 2:46, Joel Halpern wrote:
> 
> > I may be missing something, but I presume that one would have separate
> > measures.  One, if it is useful, for kWh/GB.  Presumably others for idle
> > energy consumption, etc.  And separately, one would have information
> > about what sources the site is using for its energy (or more precisely
> > if the feeds are more segregated.)
> > 
> > Yours,
> > 
> > Joel
> > 
> > On 11/11/2024 3:45 PM, Marie-Jose Montpetit wrote:
> > > I think any metric should also take into account the type of energy
> > > that is being used.  This is common in how the cost is evaluated in
> > > energy audits and there are companies who do that.  So essentially a
> > > “bit” produced on a system that uses a gas powered evergy source has
> > > not the same value a a bit produced under a wind power.
> > > 
> > > mjm
> > > Marie-José Montpetit, Ing. Ph.D.
> > > [e-mail]
> > > 
> > > 
> > > 
> > > 
> > > 
> > > > On Nov 11, 2024, at 3:13 PM, Hesham ElBakoury
> > > > <[e-mail]> wrote:
> > > > 
> > > > Dean and Tony presented set of metrics in the GREEN WG meetings
> > > > one of them is *Network Equipment Energy Efficiency* metric. I
> > > > think this is the the kWh/GB  metric which although it is used,
> > > > we debated it for quite sometime in e-impact.
> > > > 
> > > > I recall that Rudolf calls this metric nonsense and should be
> > > > banned, because "it doesn't convey any comparable and actionable
> > > > meaning. The numbers are incomparable because traffic and energy
> > > > use are in no way and have never been related. How is it
> > > > possible that with the exact same network and equipment the
> > > > energy use is stable when traffic goes up?"
> > > > 
> > > > The Journal of Industrial Ecology <http://davidmytton.blog/?action=user_content_redirect&uuid=26a31a773b7bba39c75caf0de4d5c5b2044163406de0898dfdfa2c769ab31970&blog_id=140180607&post_id=4707&user_id=244835025&subs_id=408283364&signature=6485fa34baff8ccaeb16b8eaf6822554&email_name=new-post&user_email=[e-mail]&encoded_url=aHR0cHM6Ly9vbmxpbmVsaWJyYXJ5LndpbGV5LmNvbS9qb3VybmFsLzE1MzA5Mjkw>
> > > >   published a new paper co-authored by Dag Lundén and Jens
> > > > Malmodin. 
> > Paper Title: Network energy use not directly proportional to data
> > volume: The power model approach for more reliable network energy
> > consumption calculations <http://davidmytton.blog/?action=user_content_redirect&uuid=85c1e5d13df5d1118d082181ed00f6e7a5ed7a2046c0eb8de4b50f9fb0af4d12&blog_id=140180607&post_id=4707&user_id=244835025&subs_id=408283364&signature=51744c392cee5b2ee750ad1c052559d5&email_name=new-post&user_email=[e-mail]&encoded_url=aHR0cDovL2RvaS5vcmcvMTAuMTExMS9qaWVjLjEzNTEy>
> > .
> > > > 
> > > > The idea in this paper is that many modelers have assumed a
> > > > linear relationship between data volume and energy consumption.
> > > > This fails to account for idle power consumption and other
> > > > factors. Also, networks are typically too complex to model its
> > > > energy efficiency with a number as simple as joules/bit. This
> > > > paper suggests the Power Model which has its limitations.
> > > > 
> > > > The main conclusion of the paper is that
> > > >  "There is now sufficient evidence from many organizations from
> > > > a range of different geographies to demonstrate the lack of a
> > > > connection between network usage and total energy. Combining
> > > > this with a commonsense approach that total energy of a network
> > > > device cannot exceed the total maximum power of that device and
> > > > an understanding of how networks are provisioned for redundancy
> > > > and peak capacity proves that network energy use is not directly
> > > > proportional to data volume"
> > > > 
> > > > Over the years we have seen many publications offering their
> > > > ideas and suggestions for energy efficiency metrics, but they
> > > > have their flaws and shrotcomings. I doubt there is a "perfect"
> > > > metric for systems as complex and multifaceted as a
> > > > communications network.
> > > > 
> > > > Comments?
> > > 
> 
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