Re: [E-impact] Why carbon aware routing would break the Internet and emit more carbon Re: Carbon aware routing

[Toerless Eckert <[e-mail]>]

Thanks, Rudolf for the exhaustive comment on the idea.

Wrt: "Routing traffic through Scotland doesn't make the wind blow faster in Scotland"

The energy grid is indeed used today as a great equalizier, e.g.: there are
large areas, such as typically whole countries, where the price of green vs
non-green electricity is the same whereever i am, because i just draw some
electricity from the grid and just pay indirectly for some energy production
somewhere else. And in this model of paying and sourcing electricity there
is  indeed no incentive for carbon aware routing that i could see, but instead
only an incentive for "carbon aware service pricing" that i inquired in my
prior email.

However, the underlying reality of energy networks is at least in some cases
quite different from this simplified model, and if it was not for politics,
then carbon aware routing could actually become an relevant technology option.

In Germany for example, frm my understanding there is a single merit order
pricing market, but most green energy production is in the north (wind in
the flat, coastal states), and most industrial energy consumption is in the
south. And to make things more fun, the conservative party in Bavaria
(south of Germany) managed to exploit the NIMBY stubbornness of the electorate
by rejecting normal power lines between north and south, but instead forcing
the energy grid to expand only with underground high-voltage cables, which
are something like 5 times more expensive and slower to put into place. But
this does not put the south of Germany into any worse pricing situation, because
there is a unified price across all of Germany. In result, there are times,
when wind turbines in the north have to be shut off because there is too
much powr in the northern grid, while simultaneously, south germany needs
to buy more expensive power from other southern countries because the
southern power grid is overstretched - and the consumers in the north also
pay the same highest "merit order" price.

And of course, the very same parties will not allow for the pricing north to
south to be separated to eliminate this unfairness, because that would
just speed up the move of new industries over to the north because of
the raise of prices for electricity in the south.

So, we first have to assume that pricing for electricity does actually reflect
the non-perfectness of the power grid, and we did have differences
in pricing of green energy also time based in different regions. 

We then have to assume that there is enough redundancy in the network
that we could re-route the traffic across some path with the highest
percentage of green energy  / lowest cost for them. In my limited
experience, big networks are not run with arbitrary amount of spare
capacity. So that would be the second big to make carbon aware routing
beneficial.

These are all difficult numbers, but my fear is that the pricing benefit
that could be attained is likely not worth the technical complexity
involved. Would it be possible to do this ? Yes, i think that in large
service provider networks that already use traffic engineering today
to optimize traffic capacity, energy costs and greenness at th different
locations could simply taken into account - and the stability of the
network would not change over today. But you might get some low percentage
of better greenness in energy consumption (because you can not move
a huge amount of traffic around). 

How about interdomain ? Well, there are service providers that build
interdomain paths across multiple consecutive national service
provider in different countries to create policies such as
"this traffic shall only be routed across non-chinese (Huawei/ZTE) routers".
Because this is required for overseas american companies that 
contract or otherwise get money from federal US entities. I only mention this
as a proof in point that there is no policy imaginable that
you can not do with "interdomain" routing - as long as somebody pays for it.

So if any entity with enough money to spend as the US government would put
its mind to it, i am sure the same service providers could equally build paths
agross the greenest transit hope perfectly fine as well. In both cases you would
need to source information such as "whats the vendor of the router"
or "whats the greenness consumed by the router" from some offline
information sources and then o your offline traffic engineering that
you feed back into the network. No magic involves. Its of course
some "overlay" engineered path.

How much more greenness could such a path provide over the non-engineered
interdomain path ? Hard to guess, but the less developed the power grids
are in the traversed regions, the more likely there will be local
differences, so an opportunity to explore. 

Does it make sense to put greenness into IGP metrics ? IMHO of course
not. Any type of intelligent routing these days is done as a layered
traffic engineering mechanism. 

So, i do disagree that the network would be killed by attempts to bring
green traffic engineering into it, but as long as we do not even
see the IMHO very low hanging fruit of "carbon aware network service
pricing", i don't think we will see any move in the area where actual
network traffic would change because of carbon considerations.

And what's the take on what we as e-impact / IETF could do ? 

Maybe it would make sense to create some writeup discussing thse
considerations to educate policy makers, operators, activists. But
it is quite unclear to me how such mostly financial and operational
considerations would ever make it through any of the existing trcks
toward an RFC. From recent experience it certainly does not make sense
to invest into any mayor work towards e.g.: the ISE track without
first having a clear understanding for the criteria by which the
ISE would accept it. Likewise, i do not think that any related
working group like OPSAWG would have enough of a critical mass of
supporters, unless we do source that critical mass of supporters
from the e-impact effort itself and persuade the larger OPSAWG
community that this critical mass can be driving the effort. But
right now, i do not think that e-impact people operate enough as
a group towards common goals to achieve that. Instead, its mostly
a set of different agendas.

Cheers
    Toerless

On Mon, Feb 19, 2024 at 08:29:11AM +0100, Rudolf van der Berg wrote:
> Dear all,
> 
> The graphs of Sébastien add a good extra layer to the explanation. In
> addition, I think another section might be needed to better explain what
> happens when CO2 is added as a metric.
> 
> *Routing algorithms should be personal, not universal*
> Routing algorithms are utility functions. They describe what route has the
> highest utility for the network, when it is moving traffic around. BGP is
> interesting, because it makes very little assumptions about the world
> outside the network. It particularly doesn't include metrics that are
> fixed. by outside parameters, such as distance in kilometers or carbon.
> The relative weight of the various components are individual and not the
> same for any network. The order is roughly
> - Personal rules are the most important
> - Local is best.
> - There has to be :"a route", no matter how bad
> - When there are multiple routes, all sorts of weighing can happen
> If there is an outside parameter such as distance in kilometers or carbon,
> that metric would be the same for all ASNs having traffic in a general
> direction. It is like that little road over the mountain which is very
> steep and treacherous but 10km shorter than the route around the mountain.
> The outside parameter would cause all ASNs to send all traffic along that
> route, regardless of the state of the road, how busy it is and whether it
> actually is shorter in time and effort. It might be the quickest for an
> experienced mountaineer, or a Landrover, but not for a heavily loaded
> truck.
> 
> A carbon aware routing algorithm gives the expected carbon emissions the
> priority in the utility function. As a result it would push all traffic of
> different ASNs through that route, because it has lowest emissions. Any
> changes in the network or any changes in CO2 emissions of electricity
> generation would result in an immediate and swift redirection of traffic by
> all ASNs to the new "lowest carbon" route. The algorithm wouldn't know what
> to do with congestion, costs and other metrics   It's like having an
> algorithm for picking a sweater that only looks at the colour of the
> newsreaders tie in the hourly news bulletin on TV. Everytime a new color is
> used, everyone would need to wear a sweater of that color, regardless of
> whether the color suits the wearer or the sweater at hand fits the wearer.
> Such an algorithm is unusable. If there was such an algorithm it should
> work differently for each person, based on what they have in their closet,
> age, temperature, how badly it needs to be washed etc. Those are internal
> parameters, not arbitrary external ones.
> 
> Op zo 18 feb 2024 om 11:02 schreef Sébastien Rumley <sebastien.rumley=
> [e-mail]>:
> 
> > Thanks Rudolf for this analysis.
> >
> > I'm not expert at all of BGP so will not comment on that.
> >
> > But I fully share your concerns about the need to include the electricity
> > network in the model.
> >
> > In fact, I came with a toy example that shows what you describe :
> >
> > Assume one has traffic to shift from A to Z. Assume B has many
> > carbon-extensive power sources around, while C has many low-carbon sources
> > nearby.
> >
> > Should we route the traffic through B or C ?
> >
> >    - From an energy consumption point of view, routing trough B costs
> >    only 2Watts-per-unit-of-bandwitdh (I am assuming that network resources
> >    would be turned on to carry this traffic, so we don't fall into the kWh/GB
> >    debate), while routing thru C costs twice that power.
> >    - From a CO2 perspective, now, routing thru C would be better, because
> >    wind is four times less CO2 intense. So the traffic emits half the CO2 per
> >    unit of time than thru B.
> >
> > And now... we introduce... the grid !
> >
> > Where to route now ? Thru B, because it is "internet network efficient",
> > but using the wind power of C... except (in this very simplified model) :
> >
> >    - If the grid is saturated and cannot carry the watts needed at B from
> >    C
> >    - If the power losses along the way are, in this particular example,
> >    higher than 50% (that would mean that I needed to send more than 4W from C
> >    in order to receive 2W at B).
> >
> > Actually, grids do get saturated... this is especially true between
> > countries. How to detect saturation ? Simply by noticing a difference in
> > price. If a "connector" is not saturated, there no reason to pay one price
> > at one side of the connector, and another price at the other side.
> >
> > The french grid manager, RTE, created a wonderful website where the state
> > of the network can be visualized live :
> > https://www.rte-france.com/eco2mix/les-donnees-de-marche
> >
> > This is the prices at the french connectors for today :
> >
> > The numbers atop of the chart at for 6am. Notice that the price 46.02 is
> > the same for France, Belgium, Germany, Spain, Portugal, Netherlands and
> > Austria. This means connectors are not saturated.
> >
> > As for losses, I couldn't find something better than this page which dates
> > a bit but is from a serious actor (RTE again) :
> > https://www.services-rte.com/fr/visualisez-les-donnees-publiees-par-rte/pertes-sur-le-reseau-public-de-transport.html
> > losses are said to be of the other of 2-3% at the scale of France. May be
> > at the scale of Europe losses would be higher, up to 10% because of the
> > longer distances.
> >
> >
> > So those things should be taken into account to realize proper carbon
> > aware routing, IMHO. But the subject remains interesting. Actually, this
> > has been mentioned by Dom on Friday, sometimes there is an excess of
> > renewable energy in a zone, which quickly saturates the connectors... might
> > cause the electricity price to go negative (yes it can).. and obliges the
> > operators to dissipate this power one way or another. One option is good
> > old bitcoin mining.... but another could be routing traffic.
> >
> > But there I join Rudolf's opinion : is it worth destabilizing what works ?
> > Probably not. Especially since situations with excessive green power will
> > hopefully occur less often, because more connectors are being installed,
> > and because of increased storage.
> >
> > And on that last topic : you can notice that Switzerland has a higher
> > price than the neighboring countries this morning. Why ? Very likely
> > because swiss operators have been buying electricity to pump water up in
> > the dams.. up to saturation of the French-Swiss connector.
> >
> > Best,
> >
> > Sébastien
> >
> >
> > On 17.02.24 22:53, Rudolf van der Berg wrote:
> >
> > The very interesting paper on carbon aware routing by Sawsan yesterday, of
> > which I only caught the last part of the presentation (sorry) inspired me
> > to write a more general analysis of carbon aware routing, with some
> > reference to the paper, but also a more fundamental critique of the idea of
> > carbon aware routing.
> >
> > *Why carbon aware routing would break the Internet and emit more carbon *
> >
> > *Routing isn't computer science, it is economics*
> > The science behind routing protocols is not computer science, it is
> > economics. There are thousands of actors with varying levels of dependency
> > upon each other. This is true within one network, but infinitely more so
> > between thousands of networks. These actors are all boundedly rational and
> > have varying levels of information on the state of their own and other's
> > networks in the past and at this moment. To make things more complicated,
> > their actions influence each other, can be mutually incompatible or
> > mutually beneficial. They all have different assumptions, what caused their
> > own actions and how this influenced the actions of others in the past and
> > in the future. To completely mess things up, even if all data points and
> > assumption were fully true until that point, that would not allow them to
> > predict the future state of the network and routing of traffic (not even a
> > second in the future!). It would be impossible to know whether
> > their decision is "the most optimal", because routing is part of a
> > chaotic system, called "the World". The state of the network and the
> > traffic flowing through it, is not a closed system. It is influenced by
> > everything that happens outside the network and that can be a lot, varying
> > from war, natural disasters and pestilence to human error, Taylor Swift and
> > people helping each other in times of need. That doesn't mean that the
> > system is completely random, but it can't be relied on to be stable and it
> > changes have to be expected and dealt with at any time. So the best
> > routing system is the one that requires the least complete knowledge of the
> > state of the network and can handle changes to that state at great speed
> > and with great resilience.
> >
> > The routing of traffic within one network is  determined by whoever is in
> > control of that network. No two networks need to be the same, because the
> > preferences and needs of those who control it may be different. Beautiful
> > words can be spoken, about aligning the operation of the network and
> > routing of traffic with lofty goals such as carbon awareness, customer
> > needs etc. The reality is that there are many constraints and influences
> > that will make the alignment of the daily operation of the network with
> > those beautiful words and lofty goals a matter of opinion and not fact.
> > There is therefore no most optimal way of designing a network or routing
> > traffic over it. Each network is different and therefore operates
> > differently. Interconnection of network makes it even more complex to
> > operate a network optimally.
> >
> > When it comes to cross domain routing concepts such as path dependent
> > (SCION),  carbon based, cost based, QoS based routing were all tried in the
> > 1980s and 1990s, failed and  surpassed by BGP4. All those earlier and later
> > failed routing protocols made the same flawed assumption as carbon free
> > routing does today; if I know the state of the network, I can choose the
> > most optimal route for me and the whole world. In the late eighties most
> > routing protocols required that the state of the network was known and
> > couldn't change too much. This almost broke the Internet. Fortunately
> > advances allowed BGP to be developed. It requires remarkably little
> > knowledge of the state of other networks. It can't see the difference
> > between an Autonomous System Number of BT vs JANET or Google. It doesn't
> > know what routers they use, what bandwidth there is, what physical distance
> > there is etc. It knows how to get from one ASN to another ASN. And despite
> > not knowing what a router, capacity, a telco, content provider, customer,
> > supplier, carbon, money or a country border is, it works rather well. It
> > turns out all those other variables may be very important to individuals
> > who operate one network, but aren't relevant to inter-domain routing. A
> > basic explanation I wrote of the economic transactions that take place,can
> > be found at. https://arstechnica.com/features/2008/09/peering-and-transit/
> > (This model is different and the opposite of the more often cited, but
> > flawed, two-sided models of interconnection of Laffont, Marcus, Rey and
> > Tirole)
> >
> > *Carbon aware routing in one network needs an accurate model of the
> > electricity network *
> > I'm quite sceptical of carbon aware routing within one network and even
> > more so when it happens across networks. For it to work, the routing
> > algorithm would need a full understanding of how the exhaust of carbon is
> > the result of electricity generation. The paper that was presented does not
> > have such a model as part of the CATE algorithm. The paper says that
> > national and European electricity markets are interconnected, but the
> > algorithm doesn't  derive the consequence from it: That the electricity
> > network in Scotland is to a large extent the same one as in England and is
> > interconnected with the electricity networks of EU countries. The total
> > generation is related to the total consumption in the UK and that apart
> > from losses in transport, import and export and  congestion, the total
> > electricity consumption of the UK is relevant and not the location.
> >
> >  Routing traffic through Scotland doesn't make the wind blow faster in
> > Scotland. It doesn't use less electricity in the UK.  Most low carbon and
> > zero carbon electricity sources aren't variable with demand. Their yield is
> > driven by the intensity of the wind, water and the sun. Green electricity
> > therefore has a priority over fossil fuel based electricity. Fossil fuel is
> > the back-up for what can't be generated by renewable sources. (there are
> > some renewable sources that may handle short peaks, eg water for TV-pick up
> > in the UK) So shutting down an optic from London to Leeds may save
> > electricity. This good, because it means a bit less electricity is needed
> > in total and so a little bit less non-renewable fuel needs to be burnt.
> > However, it will not lead to less carbon emitted, if shutting down a link
> > to Leeds means that for traffic to Middlesborough a link from Manchester to
> > Edinburgh and then to Middlesborough needs to be activated. The extra hop
> > and longer distance for Edinburgh would ctually increase the total
> > electricity consumption of the UK. This would require more fossil fuel to
> > be burned. Scotland's green energy is a fixed quantity. Scotland doesn't
> > become less green when traffic is routed through England. The UK does
> > become less green if more electricity is needed in total to route traffic
> > through Scotland. So a carbon aware routing protocol can only work if the
> > model of the electricity network is complete and accurate for both how
> > electricity is generated, consumed and distributed.
> >
> > *What if Scotland was independent from  England, Wales and Northern
> > Ireland, would that be better?*
> > Theoretically it could be possible that the electricity grid of Scotland
> > is completely independent of England, Wales and Northern Ireland. In that
> > case the electricity consumption and the carbon footprint would be
> > independent metrics. Scotland would need to have an over supplied and 100%
> > green grid,  completely independent of England, with no interdependence and
> > no interconnection. If at the same time England has a network that still
> > does emit CO2 in significant quantities to generate electricity, then there
> > might be a form of arbitrage possible. In this case it might be possible
> > that linking parts of BT's network in England, Wales and Northern Ireland
> > through Scotland results in less carbon emissions by the combined
> > electricity networks of Scotland, England, Wales and Northern Ireland.
> >
> > *Carbon aware routing in one network requires an accurate power profile of
> > each device in the network*
> > In the paper the authors assume that routers have a linear energy
> > consumption profile above a base load. This is an academic
> > oversimplification that is unusable in practice. Routers combine and split
> > incoming data flows so that they become outgoing data flows. The complexity
> > of a router is that incoming data flows and outgoing data flows are
> > completely different from each other in size, distribution and compilation,
> > though in aggregate they should be exactly the same. As a massive
> > intersection of roads that should have no traffic jams or crashes. As a
> > router reaches the maximum capacity of its ports and backplane its energy
> > consumption is likely to increase in a non-linear fashion, heating it up
> > more and requiring more cooling. At the same time it increasingly runs
> > against its limits. Though the likes of Google have shown that they can get
> > close to the technical limit of their networking equipment in the
> > datacenter network for their services, it is very clear that this is a
> > non-trivial task, that required a lot of upfront effort into knowing the
> > behaviour of all their equipment and of the applications that run over it.
> > https://cloud.google.com/blog/topics/systems/the-evolution-of-googles-jupiter-data-center-network
> >
> > In the case of a telecom operator such as BT, the electricity consumption
> > of the network is less deterministic. BT has a large number of very
> > different types of users and usages. It has different agreements with those
> > users. The equipment is at best of 2 different generations; the previous
> > one and the one it is moving to. Its energy consumption is in part
> > determined by physical distances, but also by weather! Certainly now
> > climate change makes it warmer and sunnier in the UK too! The network
> > changes every hour of every day, due to wear, tear, upgrades, downgrades,
> > cable breaks, equipment failure etc. All of this isn't known to BT at any
> > given moment and can take a while to percolate through to configuration
> > databases at which point the state of the network is already different.
> >
> > What the CATE algorithm tries to do therefore falls far short of what
> > would be needed, because it makes linear assumptions and assumes a stable
> > state of BTs network, while not correctly incorporating the operation of
> > the electricity network.
> >
> > *Carbon aware routing across independent networks will break the Internet*
> > Routing based on BGP makes use of Autonomous Systems and how many hops
> > there are between the source ASN and the target ASN. Less hops is better.
> > BGP doesn't make assumptions about what an ASN represents. BGP doesn't know
> > anything about how many routers, how much capacity, how many miles or how
> > much traffic is in each ASN. Between the more than 75K ASNs there are
> > continuous changes and BGP will announce them and algorithms will process
> > them. It is a dumb, but scalable system, with a remarkably efficient and
> > scalable network of interconnected networks as an emergent property.
> >
> > Carbon awareness would require that the routing algorithm actually knows
> > and understands the electricity network that each piece of equipment in the
> > entire Internet. Everything that should have been done in the BT network
> > for the CATE algorithm to have reliable results, but then for every
> > autonomous system and all the networks comprising those ASNs.
> >
> > What would really break the Internet however is that if carbon is used as
> > a metric to guide routing decisions, than certain paths will always emerge
> > as the most optimal from a carbon perspective. This is clear from the
> > lament of the authors about the Geant network relying so much on Germany
> > for its connectivity and Germany having such high carbon emissions. If
> > carbon aware routing was a thing on the Internet, all traffic would want to
> > evade networks that run through Germany (or not if they actually understand
> > that Europe has an interconnected electricity market). What would happen is
> > that traffic would seek the route with the lowest carbon emissions and all
> > traffic would be sent to that route, without consideration for capacity,
> > costs etc. That route would be overloaded, of which it would have to alert
> > other networks, but those wouldn't be able to determine which network can
> > and which network shouldn't send its traffic over the saturated, but lowest
> > carbon, link.
> >
> > A similar issue was relayed to me by ISOC staff after the great earthquake
> > in Japan, where most links had broken and therefore limited capacity was
> > available. Japanese telecom firms had sold more "guaranteed" capacity than
> > there was capacity available in the affected area. The result was that the
> > routers wouldn't know what network had priority and therefore transmitted
> > no traffic at all, despite total traffic being less than what little
> > capacity was left. After the earthquake businesses were closed and most
> > people were either in shelters hiding or doing practical things for the
> > recovery and therefore the network was less in use.
> >
> > Carbon, QoS and other such metrics are of little use in routing across
> > autonomous systems. Each network is different and has its own operations.
> > The success of the Internet is that BGP doesn't have to factor it all in.
> >
> > *Electricity aware networking not carbon aware routing *
> > The paper does show a more practical approach limiting the negative impact
> > of use of resources by networks. By looking at the electricity consumption
> > of links and interfaces and the amount of traffic, there can be a reason to
> > turn off certain interfaces and equipment during moments of low use. Even
> > this is non-trivial, because of non-linear effects, redundancy and the ever
> > changing state of the network and the performance of equipment. Looking at
> > operational electricity consumption is probably difficult enough for
> > network staff to deal with. Embedded carbon of new versus old equipment
> > might be too complex already. To illustrate, a network may supply
> > connectivity to a customer through 2 times 2x100Gbps on a redundant route
> > between two towns. The peaks exceed 100Gbps on the link, but not by much
> > and traffic growth can be limited. 2 times 400Gbps will then use less
> > electricity at any moment. This can be calculated and demonstrated. The
> > embedded carbon of earlier replacement of interfaces, combined with the
> > network being able to use 2 ports for another customer are much more
> > complex, particularly when the 100Gbps is used elsewhere in the network.
> >
> > *Carbon aware placement of datacenters*
> > Transport losses, congestion and other examples of inefficiency and
> > scarcity in real world electric networks might make it preferable to build
> > sites that consume a lot of electricity close to where the generation is
> > greenest. That however applies to BT's peers and not to BT itself. BT is a
> > nationwide network. Its electricity consumption primarily follows where
> > people live and work. That typically is England and not Scotland. So
> > placing a government or hyperscale datacenter in Glasgow might be preferred
> > over Slough from a carbon aware electricity generation point of view.
> > Transmitting photons over optical fibre uses less electricity than the
> > losses of the electricity network over the same distance.
> >
> > *Conclusion*
> > The impact of networking on the planet is significant. Every attempt
> > should be made to decrease the impact whether it is from the operation of
> > the network or building, upgrading and replacing it. Using less electricity
> > in networking is good, because it means that less electricity needs to be
> > generated, whether it is through sustainable or unsustainable generation.
> > Making routing decisions depend on assumed carbon emissions is however not
> > going to lead to less energy consumption, less carbon emessions or better
> > routing and networking. It will likely break the Internet and emit more
> > carbon. Better awareness of electricity consumption and the lifetime of
> > equipment is what the internet community can work on.
> >
> >
> >
> > Op za 17 feb 2024 16:57 schreef Hesham ElBakoury <[e-mail]>:
> >
> >> Actually this Seyedali et al paper (from Adrian SCION group) is
> >> referenced by Salwa et al paper (from Noa group).
> >> The comment made by Salwa's paper says that SCION paper "*takes
> >> advantage of the SCION architecture in the context of path-aware networks.
> >> It derives an estimated*
> >> *carbon footprint for every inter-domain path and then, end-domains
> >> choose the paths with the least emissions. This should not be confused with
> >> the network-wide carbon optimization problem that removes any overlapping
> >> between end-domains*".
> >>
> >> There are many papers about green routing and green traffic engineering.
> >> As Salwa pointed out in her presentation, each has its own limitations.
> >>
> >> Hesham
> >>
> >> On Sat, Feb 17, 2024, 6:21 AM Michael Welzl <[e-mail]> wrote:
> >>
> >>> … and then there was also this:
> >>> https://netsec.ethz.ch/publications/papers/green_routing2023.pdf
> >>>
> >>> Cheers,
> >>> Michael
> >>>
> >>>
> >>>
> >>> On Feb 17, 2024, at 1:37 AM, Eve Schooler <[e-mail]>
> >>> wrote:
> >>>
> >>> Thanks Hesham!
> >>> The paper first appeared in HotCarbon'22, and was re-published along
> >>> with many other papers from that workshop in the ACM SIGEnergy Energy
> >>> Informatics Review this past Oct 2023.
> >>> --Eve
> >>>
> >>> On Fri, Feb 16, 2024 at 3:50 PM Hesham ElBakoury <[e-mail]>
> >>> wrote:
> >>>
> >>>> I also recall that Noa and Eve had a paper on carbon aware networking
> >>>> https://dl.acm.org/doi/10.1145/3630614.3630618. It is also a good
> >>>> paper.
> >>>>
> >>>> It is worth noting that section 8.6 of Sawdan and Noa paper provides a
> >>>> comparison with the state of the art. "In summary, this paper looked at
> >>>> practical current considerations, different to assumptions in previous
> >>>> works. It estimated similar carbon savings while accounting for more
> >>>> fine-grained carbon
> >>>>  intensity data, technical operating considerations of routers, without
> >>>> assumptions on additional renewable energy deployments."
> >>>>
> >>>> Hesham
> >>>>
> >>>> On Fri, Feb 16, 2024, 12:47 PM Rudolf van der Berg <
> >>>> [e-mail]> wrote:
> >>>>
> >>>>>
> >>>>> https://ora.ox.ac.uk/objects/uuid:504d0a87-6742-414f-b2c2-be74f2e5b579/files/sc821gm64z
> >>>>>
> >>>>> Op vr 16 feb 2024 20:30 schreef Chris Adams <
> >>>>> [e-mail]>:
> >>>>>
> >>>>>> Hi folks,
> >>>>>>
> >>>>>> > We had good presentation today on carbon aware routing. More
> >>>>>>> details on
> >>>>>>> > carbon aware routing are provided in this paper:
> >>>>>>> > https://dl.acm.org/doi/10.1145/3629165
> >>>>>>>
> >>>>>>
> >>>>>> I’m not part of an institution with access to that paper at that url
> >>>>>> - would a kind soul point me to somewhere I can download it, or share a
> >>>>>> copy with me? I’m very interested in reading it.
> >>>>>>
> >>>>>> Thanks in advance.
> >>>>>>
> >>>>>> Chris Adams
> >>>>>>
> >>>>>> Executive Director
> >>>>>>
> >>>>>> w: thegreenwebfoundation.org
> >>>>>> e: [e-mail]
> >>>>>> t: @mrchrisadams
> >>>>>>
> >>>>>> German Office
> >>>>>> Naunynstrasse 40
> >>>>>> 10999 Berlin
> >>>>>> Germany
> >>>>>>
> >>>>>> See our contact page for more details
> >>>>>> https://www.thegreenwebfoundation.org/contact/
> >>>>>>
> >>>>>> Book a short call with me to discuss something.
> >>>>>> https://cal.com/mrchrisadams
> >>>>>>
> >>>>>>
> >>>>>> On 16. Feb 2024, at 20:03, Dirk Trossen <dirk.trossen=
> >>>>>> [e-mail]> wrote:
> >>>>>>
> >>>>>> CATS, although compute aware,  could incorporate energy metrics in
> >>>>>> its approach to traffic steering.
> >>>>>>
> >>>>>> In fact,  we had discussed previously in CATS work that I published
> >>>>>> in IFIP Networking 2021 that utilised a cardinal based WFQ at ingress
> >>>>>> points to dynamically steer traffic. We're currently looking into the right
> >>>>>> utility function for energy to replace the compute units we used back in
> >>>>>> 2021.
> >>>>>>
> >>>>>> Dirk
> >>>>>>
> >>>>>>
> >>>>>>
> >>>>>>
> >>>>>> *From:*Hesham ElBakoury <[e-mail]>
> >>>>>> *To:*Toerless Eckert <[e-mail]>
> >>>>>> *Cc:*E-Impact IETF <[e-mail]>
> >>>>>> *Date:*2024-02-16 19:03:35
> >>>>>> *Subject:*Re: [E-impact] Carbon aware routing
> >>>>>>
> >>>>>> Tvr is my preference as we discussed upon tvr inception. But I think
> >>>>>> in today's meeting IRTF was mentioned as the venue for this discussion.
> >>>>>>
> >>>>>> Hesham
> >>>>>>
> >>>>>> On Fri, Feb 16, 2024, 9:57 AM Toerless Eckert <[e-mail]> wrote:
> >>>>>>
> >>>>>>> IRTF not sure, but IETF TVR:
> >>>>>>>
> >>>>>>> >From charter:
> >>>>>>>
> >>>>>>> "Similarly, network traffic might be routed based on energy costs or
> >>>>>>> expected user data volumes, which may vary predictably over time in
> >>>>>>> networks prioritizing green computing and energy efficiency."
> >>>>>>>
> >>>>>>> Cheers
> >>>>>>>     Toerless
> >>>>>>>
> >>>>>>> On Fri, Feb 16, 2024 at 09:49:03AM -0800, Hesham ElBakoury wrote:
> >>>>>>> > We had good presentation today on carbon aware routing. More
> >>>>>>> details on
> >>>>>>> > carbon aware routing are provided in this paper:
> >>>>>>> > https://dl.acm.org/doi/10.1145/3629165
> >>>>>>> >
> >>>>>>> > Which IRTF group is suitable to discuss this topic More?
> >>>>>>> >
> >>>>>>> > Thanks
> >>>>>>> > Hesham
> >>>>>>>
> >>>>>>> > --
> >>>>>>> > E-impact mailing list
> >>>>>>> > [e-mail]
> >>>>>>> > https://www.ietf.org/mailman/listinfo/e-impact
> >>>>>>>
> >>>>>> --
> >>>>>> E-impact mailing list
> >>>>>> [e-mail]
> >>>>>> https://www.ietf.org/mailman/listinfo/e-impact
> >>>>>>
> >>>>>>
> >>>>>> --
> >>>>>> E-impact mailing list
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> >>>>>> https://www.ietf.org/mailman/listinfo/e-impact
> >>>>>>
> >>>>> --
> >>>> E-impact mailing list
> >>>> [e-mail]
> >>>> https://www.ietf.org/mailman/listinfo/e-impact
> >>>>
> >>> --
> >>> E-impact mailing list
> >>> [e-mail]
> >>> https://www.ietf.org/mailman/listinfo/e-impact
> >>>
> >>>
> >>> --
> >> E-impact mailing list
> >> [e-mail]
> >> https://www.ietf.org/mailman/listinfo/e-impact
> >>
> >
> > --
> > Dr. Sébastien RUMLEY, Professor
> > iCoSys Institute, part of
> > HEIA-FR - School of Engineering and Architecture - Fribourg, part of
> > HES-SO - University of Applied Sciences and Arts Western Switzerland
> >
> > --
> > E-impact mailing list
> > [e-mail]
> > https://www.ietf.org/mailman/listinfo/e-impact
> >





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