towards energy efficient internet service providers – econet perspective

low Energy COnsumption NETworks

Towards energy efficient Internet Service Providers – ECOnet Perspective

Constantinos [email protected]

Greek Research and Technology Network

Utrecht, Netherlands, 5-6 March 2012 GN3 Green Networking: Advances in Environmental Policy and Practice

mailto:[email protected]

GN3 Green Networking: Advances in Environmental Policy and Practice

Outline The ECONET Project Energy consumption and energy efficiency

demand Decomposing the Energy Consumption in the

Wired Network A Taxonomy of Undertaken Approaches ECONET approach Potential Impact on the Wired Network

Utrecht, Netherlands, 5-6 March 2012



Increasing the energy efficiency and the sustainable growth of our world is a global process where Telecommunications technologies (and the ICTs in general) play a key role.

But to obtain optimum results the process should involve the “two faces of the same coin”:– Green ICT – reducing the carbon footprint of ICT– ICT for Green – using ICT for reducing third party-

wastes. ECONET is dealing with the first aspect

– Focused on short and medium time exploitation

The ECONET project



Participant organisation name Short name Country

Consorzio Nazionale Interuniversitario per le Telecomunicazioni – UdR at DIST University of Genoa (Coordinator) CNIT Italy

Mellanox Technologies MLX IsraelAlcatel Lucent ALU ItalyLantiq LQDE GermanyEricsson Telecomunicazioni S.p.A. TEI ItalyTelecom Italia TELIT ItalyGreek Research & Technology Network GRNET GreeceResearch and Academic Computer Network NASK PolandDublin City University DCU IrelandVTT Technical Research Centre VTT FinlandWarsaw University of Technology WUT PolandNetVisor NVR HungaryEthernity ETY IsraelLightComm LGT ItalyInfoCom INFO Italy

Manufacturers

Operators

Academic /research centers

Small/Medium Enterprises (SMEs)

The

Cons

ortiu

mThe ECONET project



Goals: re-thinking and re-designing network equipment towards more energy-sustainable and eco-friendly technologies and perspectives. The overall idea is to introduce novel green network-specific

paradigms and concepts enabling the reduction of energy requirements of wired network equipment by 50% in the short/mid-term (and by 80% in the long run) with respect to the business-as-usual scenario.

To this end, the main challenge is to design, develop and test novel technologies, integrated control criteria and mechanisms for network equipment allowing energy saving by dynamically adapting the device capacities and consumptions to current traffic loads and user requirements.

The ECONET project



Energy consumption and energy efficiency demand

There are two main motivations that drive the quest for “green” ICT: – the environmental one, which is related to the reduction of wastes,

in order to impact on CO2 emission; – the economical one, which stems from the reduction of operating

costs (OPEX) of ICT services.

Gartner Group, Inc. (2007)“The global information and communications technology (ICT) industry accounts for approximately 2% of global carbon dioxide (CO2) emissions, a figure equivalent to aviation.”

Note that the ICT sector raises much faster than aviation

How much is 2% of CO2?




The figures refer to the whole corporate consumption. As such, they account for numerous sources, other than the operational absorption of the networking equipment (e.g., offices’ heating and lights). Notwithstanding, they give an idea of the general trend.




Electrical energy consumption evolution and future trends for TELIT’s fixed network. Source: Telecom Italia

‘84 ‘88 ‘92 ‘96

GWh

Years‘98 ‘10‘08

Start of network digitalization

End of network digitalization

E TOT

E TLC

Fixed network domain

E TOT: total energy consumption from mains (TLC equipment, cooling, ausiliary systems) E TLC: energy consumption of TLC equipment

End user appliancesPower Consumption

New challenge on energy savingNeed of further actions on TLC equipments

Energy consumption became a Key Issue

Start ADSL deployment

Source: C. Bianco, F. Cucchietti, G. Griffa, ” Energy consumption trends in the Next GenerationAccess Network - a Telco perspective, ” IEEE INTELEC 2007.



Decomposing the Energy ConsumptionThe Wired Network

Typical access, metro and core device density and energy requirements in today’s typical networks deployed by telcos, and ensuing overall energy requirements of access and metro/core networks.

Source: R. Bolla, R. Bruschi, F. Davoli, F. Cucchietti, “Energy Efficiency in the Future Internet: A Survey of Existing Approaches and Trends in Energy-Aware Fixed Network Infrastructures,” IEEE Communications Surveys & Tutorials, vol. 13, no. 2, pp. 223-244, 2nd Qr. 2011.



Decomposing the Energy Consumption High-end Routers

Estimate of power consumption sources in a generic platform of high-end IP router.

Source: R. Tucker, “Will optical replace electronic packet switching?”, SPIE Newsroom, 2007.



Decomposing the Energy Consumption Is the energy consumption currently load-dependent?

Network engineers only speak about the capacity of a device or of a link interface…

…as a matter of fact, device and link are specifically designed to work at the maximum speed…Source: The ECONET Consortium, ”End-user requirements, technology specifications and benchmarking methodologies,” Deliverable 2.1.

Power consumption in GRNET core routers (24-hour period)Daily traffic profile of core GRNET network router (peering with GEANT)



Decomposing the Energy Consumption Is the energy consumption currently load-dependent?

Power Consumption of Cisco Catalyst 2970 Switch

Source: K. Christensen, P. Reviriego, B. Nordman, M. Bennett, M. Mostowfi, J.A. Maestro, "IEEE 802.3az: the road to energy efficient ethernet," IEEE Communications Magazine, vol.48, no.11, pp.50-56, November 2010.

1. There is no significant difference in power consumption whether a port is running at 10 Mbps or 100 Mbps.

2. The switch power consumption is increased by connecting a new link, even if there is no data being transmitted on this link.

3. The difference in power consumption is quite low when a 1 Gbps link is fully utilized compared to when it is zero utilized.



Decomposing the Energy Consumption Day & Night Traffic Profiles

Percentage w.r.t. peak level. The profiles exhibit regular, daily cyclical traffic patterns with Internet traffic dropping at night and growing during the day.

Traffic load fluctuation at peering links for about 40 ISPs from USA and Europe

Source: http://asert.arbornetworks.com/2009/08/what-europeans-do-at-night/



Decomposing the Energy Consumption Energy wastes

Networks and devices are lightly utilized.o Often peak loads during rush hours are generally much lower

than capacities of links and devices.• It is well known that the «overdimensioning» is the best

design strategy for assuring QoS levels…o Moreover, traffic loads follow well-known day & night

fluctuations. On the other hand, the energy requirements of network

devices remain substantially flat according to their workload.

Furthermore, networks are highly overprovisioned /redundant to assure service availability.



A Taxonomy of Undertaken Approaches

Source: R. Bolla, R. Bruschi, F. Davoli, F. Cucchietti, “Energy Efficiency in the Future Internet: A Survey of Existing Approaches and Trends in Energy-Aware Fixed Network Infrastructures,” IEEE Communications Surveys & Tutorials, vol. 13, no. 2, pp. 223-244, 2nd Qr. 2011.

The largest part of undertaken approaches regarding engineered improvements is funded on few base concepts, which have been generally inspired by energy-saving mechanisms and power management criteria that are already partially available in computing systems.



Re-engineering approaches aim at: – introducing and designing more energy-efficient

elements for network device architectures– suitably dimensioning and optimizing the internal

organization of devices– reducing their intrinsic complexity levels.

A Taxonomy of Undertaken ApproachesRe-engineering



The dynamic adaptation of network/device resources is designed to modulate capacities of packet processing engines and of network interfaces, to meet actual traffic loads and requirements.

This can be performed by using two power-aware capabilities, namely, dynamic voltage scaling and idle logic, which both allow the dynamic trade-off between packet service performance and power consumption.

A Taxonomy of Undertaken ApproachesDynamic Adaptation



Standard operations

Idle logic

Power scaling

Idle + power scaling

Wakeup and sleeping times

Increased service times

Wakeup and sleeping + increased service times

A Taxonomy of Undertaken ApproachesDynamic Adaptation


First version: Adaptive Link Rate proposed by Christensen and Nordman

Final Version: based on the “low power idle” concept, proposed by Intel.Idea: transmit data at the maximum speed, and put the link to sleep when it is idle.

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A Taxonomy of Undertaken ApproachesDynamic Adaptation: Green Ethernet (IEEE 802.3 az)

Tw and Ts for 10 Gb/s in IEEE Std 802.3az-2010 are 4.48 μs and 2.88 μs, respectively

LPI can possibly be asynchronous



In PC-based devices, the Advanced Configuration and Power Interface (ACPI) provides a standardized interface between the hardware and the software layers.

ACPI introduces two power saving mechanisms, which can be individually employed and tuned for each core:– Power States (C-states)

• C0 is the active power state• C1 through Cn are processor sleeping or idle states (where the processor

consumes less power and dissipates less heat).– Performance States (P-states)

• while in the C0 state, ACPI allows the performance of the core to be tuned through P-state transitions.P-states allow to modify the operating energy point of a processor/core by altering the working frequency and/or voltage, or throttling the clock.

A Taxonomy of Undertaken ApproachesDynamic Adaptation: SW routers & ACPI



21

Source: R. Bolla, R. Bruschi, A. Ranieri, “Green Support for PC-based Software Router: Performance Evaluation and Modeling”, Proc. IEEE ICC 2009, Dresden, Germany, June 2009. Best Paper Award.

[MHz]

A Taxonomy of Undertaken ApproachesDynamic Adaptation: SW routers & ACPI



Sleeping/standby approaches are used to smartly and selectively drive unused network/device portions to low standby modes, and to wake them up only if necessary.

However, – since today’s networks and related services and

applications are designed to be continuously and always available,

– standby modes have to be explicitly supported with special techniques able to maintain the “network presence” of sleeping nodes/components.

A Taxonomy of Undertaken ApproachesSleeping/Standby



Scenario: networked hosts (PCs, consumer electronics, etc.); Problem: when an end-host enters standby mode, it freezes

all network services, and it is not able to maintain its network presence;

Idea: introduce a Network Connection Proxy (NCP), which is devoted to maintain the network presence of sleeping hosts.

Sleeping host NCP Internet

Continuous and full connectivity

Wakeup/sleepmessages

Application-specific messages

Zzzzz…I want to

sleep

Source: M. Allman, K. Christensen, B. Nordman, V. Paxson, “Enabling an Energy-Efficient Future Internet Through Selectively Connected End Systems,” Proc. ACM SIGCOMM HotNets, Atlanta, GA, Nov. 2007.

A Taxonomy of Undertaken ApproachesSleeping/Standby: Proxying the Network Presence



Scenario: Core Networks Idea: put links, interfaces and part of nodes (e.g., line-cards) to

sleep Problem: Network stability, convergence times at multiple

levels (e.g., MPLS traffic engineering + IP routing)

Source: R. Bolla, R. Bruschi, A. Cianfrani, M. Listanti, “Putting Backbone Networks to Sleep,” IEEE Network Magazine, Special Issue on “Green Networking”, vol. 25, no. 2, pp. 26-31, March/April 2011.




Solution: they exploited two features already present in today’s networks and devices: – network resource virtualization– modular architecture of network nodes.

This approach allows to:– Put physical resources to sleep (e.g., links, linecards, etc.);– Move the logical entities working on physical elements going to

sleep, to other physical elements on the device. If suitable L2 protocols are used, the complexity of

standby management can be hidden from the IP layer, and totally managed inside traffic engineering procedures.




Standby states have usually much lower energy requirements than active states.

Network-wide control strategies (i.e., routing and traffic engineering) give the possibility of moving traffic load among network nodes.

When a network is under-utilized, we can move network load on few “active” nodes, and put all the other ones in standby.

– Different network nodes can have heterogeneous energy capabilities and profiles.

Recent studies, obtained with real data from Telcos (topologies and traffic volumes) suggested that network-wide control strategies could cut the overall energy consumption by more than 23%.

Standby state

Performance scaling

Pow

er C

onsu

mpti

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Energy-aware state


A Taxonomy of Undertaken ApproachesGreen network-wide control: Traffic engineering & routing


Only local control policies Local + network-wide control policies

Once network devices will include energy management primitives, further energy reduction will be possible by moving traffic flows among the network nodes, in order to minimize the energy consumption of the entire infrastructure.


A Taxonomy of Undertaken ApproachesGreen network-wide control: Traffic engineering & routing



The ECONET approach



Green Abstraction Layer

The ECONET approach



The ECONET approach

ECONET Test Bench@ TELIT Test Plant



Potential Impact on the Wired Network

The previously mentioned green technologies allow designing new-generation network devices characterized by “energy profiles”

Reference: R. Bolla, R. Bruschi, A. Carrega, F. Davoli, D. Suino, C. Vassilakis, A. Zafeiropoulos, “Cutting the Energy Bills of Internet Service Providers and Telecoms through Power Management: an Impact Analysis”, Elsevier Computer Networks, Special Issue on “Green Communication Networks”, to appear



Potential Impact on the Wired NetworkTELIT reference scenario

Network load statistics and topology data

2015-2020 network forecast: device density and energy requirements(example based on Italian network)

customers per DSLAM 640average usage of a network access 30%

average traffic when a user is connected 10%

redundancy degree for metro/transport devices 13%redundancy degree for core devices 100%

redundancy degree of metro/transport device links 100%

redundancy degree of core device links 50%average traffic load in metro networks 40%average traffic load in core networks 40%

standby efficiency 85% performance scaling efficiency 50%

network-wide control efficiency 20% air cooling/power supply efficiency 15%

Home/Access

Metro/Transport/Core

target

Source: forecast based on: carrier grade topologies; traffic analysis and indicators (ETSI TR 102530, ODYSSEE) and projected traffic load.

power consumption (Wh) number of devices overall consumption (GWh/year)Home 10 17,500,000 1,533Access 1,280 27,344 307

Metro/transport 6,000 1,750 92Core 10,000 175 15

Sources: 1) BroadBand Code of Conduct V.3 (EC-JRC) and “inertial” technology improvements to 2015-2020 (home and access cons.)2) Telecom Italia measurements and evaluations (power consumption of metro/core network and number of devices)

Data Plane Control Plane Cooling/Power SupplyHome 79% 3% 18%Access 84% 3% 13%

Metro/transport 73% 13% 14%Core 54% 11% 35%

Device internal sources of energy consumption

Sources: Information from vendors.

Sources: BroadBand Code of Conduct V.3 (EC-JRC) and technology improvements to 2015-2020.



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Typical traffic Profile for a business link

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Potential Impact on the Wired NetworkTELIT network topology and traffic profiles



Yearly Energy consumption estimation for TELIT

Potential Impact on the Wired NetworkIs There Room for Energy Saving Optimization?

Room for Energy Saving Optimization

Home/access Metro/Transport Core



Potential Impact on the Wired NetworkEnergy consumption model outline

Source: R. Bolla, R. Bruschi, A. Carrega, F. Davoli, D. Suino, C. Vassilakis, A. Zafeiropoulos, “Cutting the Energy Bills of Internet Service Providers and Telecoms through Power Management: an Impact Analysis”, Elsevier Computer Networks, Special Issue on “Green Communication Networks”, to appear



DPS primitives only Standby primitives only

DPS & Standby primitives

Potential Impact on the Wired NetworkEstimated energy saving for the TELIT network

We suppose standby capabilities to be applied only where “alternative paths” are present.



Potential Impact on the Wired NetworkThe GRNET network case

Yearly Energy consumption estimation for GRNET

DPS & Standby primitives

GRNET network does not have Access/Home parts

low Energy COnsumption NETworks

GN3 Green Networking: Advances in Environmental Policy and PracticeUtrecht, Netherlands, 5-6 March 2012

Thank you for your attention!

Questions?

[email protected]

http://econet-project.eu

http://green.grnet.gr

mailto:[email protected]

http://econet-project.eu/

http://green.grnet.gr/



Utrecht, Netherlands, 5-6 March 2012Utrecht, Netherlands, 5-6 March 2012 GN3 Green Networking: Advances in Environmental Policy and Practice

Backup slides



Decomposing the Energy Consumption Access Technologies

Power consumption of DSL, HFC, PON, FTTN, PtP, WiMAX, and UMTS as a function of access rate with an oversubscription rate of 20. The technology used is fixed at 2010 vintage for all access rates.

Source: Baliga, J.; Ayre, R.; Hinton, K.; Tucker, R.S.; , "Energy consumption in wired and wireless access networks," IEEE Communications Magazine, vol. 49, no. 6, pp. 70-77, June 2011.



Adoption of pure optical switching architectures:– They can potentially provide terabits of bandwidth at much lower

power dissipation than current network devices. – But their widespread adoption is still hindered by technological

challenges: problems mainly regard the limited number of ports and the feasibility of suitable buffering schemes.

Decreasing feature sizes in semiconductor technology have contributed to performance gains: – allowing higher clock frequencies – designing improvements such as increased parallelism. – the same technology trends have also allowed for a decrease in voltage

that has reduced the power per byte transmitted by half every two years, as suggested by Dennard’s scaling law.

A Taxonomy of Undertaken ApproachesRe-engineering


Source: R. Bolla, R. Bruschi, A. Carrega, F. Davoli, “Green Network Technologies and the Art of Trading-off,” Proc. IEEE INFOCOM 2011 Workshop on Green Communications and Networking, Shanghai, China, April 2001, pp. 301-306.

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A Taxonomy of Undertaken ApproachesDynamic Adaptation: Understanding the Power-Performance Tradeoff

Modeling and control

Recently a simple model has been proposed by Bolla et al, which is based on classical queueing theory and allows representing the trade-off between energy and network performance in the presence of both AR and LPI capabilities.

The model is aimed at describing the behaviour of packet processing engines.

It is based on a Mx/D/1/SET queueing system.



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A Taxonomy of Undertaken ApproachesDynamic Adaptation: Understanding the Power-Performance Tradeoff

Modeling and control




A Taxonomy of Undertaken ApproachesRe-engineering: Optical Backbone Networks

The creation of optical paths (via DWDM) within optical backbone networks has been utilized for the dynamic establishment of high capacity circuits with reduced energy demands



Standardization efforts

The European Union already published a number of Codes of Conduct – covering different categories of equipment, including broadband equipment, data centres, power supplies, UPS. The

Code of Conduct on Energy Consumption of Broadband Equipment has been defined by the EU, which sets targets in reducing energy consumption in the access network

IEEE has also ratified the Energy Efficient Ethernet (EEE) standard in October 2010, also known as IEEE 802.3az,

– which is a set of enhancements to the twisted-pair and backplane Ethernet networking standards that will allow for more than 50% less power consumption during periods of low data activity, while retaining full compatibility with existing equipment.

ENERGY STAR is a joint program of the U.S. Environmental Protection Agency and the U.S. Department of Energy that has defined the ENERGY STAR Product Specifications.

IETF has recently established the Energy Management (EMAN) Working Group. Different interesting issues are under consideration by the Environmental Engineering

Technical Body in ETSI The Home Gateway Initiative (HGI) launched an internal task force called ”Energy Saving” with

the objective of setting up requirements and specifications for energy efficiency in the home gateways

ITU-T Study Group 15 (Optical transport networks and access network infrastructures) ITU-T created in September 2008 a new Focus Group, namely, FG ICT & Climate Change



ECONET approach

towards energy efficient internet service providers – econet perspective

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