Evaluation of Power Rating of Core Network Equipment in Practical Deployments

Transcription

1 Evaluation of Power Rating of Core Network Equipment in Practical Deployments Ward Van Heddeghem a, Filip Idzikowski b, Esther Lerouzic c, Jean Yves Mazeas c, Hubert Poignant c, Suzanne Salaun c, Bart Lannoo a, Didier Colle a Greencom online conference 28 October 2012, (c) (b) (a)

2 What is the problem? Increasing number of publications on energy-efficient networks, see Important to have good reference power values for network equipment. For example, optical amplifier: in [1]: 0.5 W / wavelength in [2]: W / wavelength Source: WebOfScience Topic=((green OR "energy efficient" OR "energy-efficient") AND network*) See our earlier work at [1]: Shen, JOCN, 2009, [2]: Chiaraviglio, GreenCom

3 What is the problem? Increased usage of power/capacity, e.g. 5 W/Gbps for a transponder But these are usually based on maximally filled configurations, i.e. a card in all slots, optimally sharing overhead power D. Kilper, Power Trends in Communication Networks, JSTQE

4 What is the problem? IP router: Cisco CRS-1 16 slot WDM equipment: Alcatel 1626 LM 4

5 What is the problem? But is the shelf/rack always fully filled? Probably not Goal: Can we figure out an average correction factor for those optimal Watt/Gbps ratings, based on given filling rate over time and equipment lifetime? Metric: power rating correction factor i.e, difference from optimal power rating Power values: based on data sheets and measurements 5

6 (de)mux Considered equipment Core Network Data Center Amsterdam Brussels IP router London OLA Frankfurt LC LC Paris Bern End User Equipment (Home/Office) core IP router Access Network LC LC LC Line cards Transponders Booster/pre amp line amplifier 80 km WDM terminal OLA 6

7 Power rating correction factor IP router Metric: power rating correction factor i.e, difference from optimal power rating W/Gbps 21 W/Gbps Juniper T1600 Cisco CRS-3 16slot W/Gbps (Juniper) 4.9 W/Gbps (Cisco) Compare 16-slot Cisco and Juniper single chassis router % 20% 40% 60% 80% 100% Equipment filling Only 1 line card Bad power rating Completely filled shelf Optimal power rating 7

8 Power rating correction factor Equipment filling (%) IP router IP traffic growth: 40-50% per year Filling: doubles every 2 years (CAGR: 41%) Power rating correction factor (CRS-3) Equipment filling 100% 90% 80% 70% Lifetime: assume 8 years (France Telecom: varies a lot, but probably less) % 50% 40% 30% 20% 10% Map power rating correction factor using previous chart Year 0% 8

9 Power rating correction factor Equipment filling (%) IP router Average over lifetime of 8 years? Cisco CRS-3: 1.77x Power Power rating rating correction correction factor factor (CRS-3) (CRS-3) Avg. power rating corr. factor (CRS-3) Equipment Equipment filling filling 100% 90% 80% 70% Juniper T1600: 1.92x % 50% 40% % % 10% 1.85x Year 0% 9

10 IP routers an example What does this mean? An example: Say your Cisco router s data sheet has: a maximum capacity of 1000 Gbps A power consumption at maximum capacity of 5000 Watt Power rating = 5 Watt/Gbps In real life, deployed Cisco routers will have a average power rating of approximately : 1.85 x 5 Watt/Gbps = 9 Watt/Gbps 10

11 Power rating correction factor WDM terminal 80-channel WDM terminal: W/Gbps (40G) 10G Vary number of installed transponders (0 80) W/Gbps (10G) 4.8 W/Gbps 4.7 W/Gbps (10G) 4.4 W/Gbps (40G) 4.0 W/Gbps (100G) 40G 100G % 20% 40% 60% 80% 100% Equipment filling (100% corresponds to 80 channels) 11

12 Power rating correction factor Equipment filling WDM terminal Evolution over time Same assumption as for IP (double every 2 years and lifetime 8 years) Less correction than IP Reason: relative less overhead power consumption (= more power proportional) Power rating correction factor (10G) Avg. power rating corr. factor (10G) Equipment filling Year 100% 90% 80% 70% 60% 50% 40% 30% 20% 10% 0% 12

13 Power rating correction factor OLA (optical line amplifiers) Same exercise for OLAs? bidir OLA 3 shelves (vendor A) 1 shelf (vendor B) No! bidir OLAs France Telecom: in practice, only 1 (max 2) bidir OLA per amplification site. Poor ratings! 1.5x to 1.8x optimal bidir OLAs 10 bidir OLAs 0% 20% 40% 60% 80% 100% Equipment filling Based on vendor data sheets: see 13

14 Summary (for filling) Correction factor from optimal [W/Gbps] value Optimal IP router 1.85 IP: 1.9x WDM terminal, 10G/40G WDM terminal, 100G WDM term: 1.1x-1.2x OLA 1.50 OLA: 1.5x Power rating correction factor 14

15 Influence of load on power rating How does the power, and power rating, vary with varying load (or throughput)? Power: varies, but not a lot (e.g. IP router measurements ) Power rating: does not vary, capacity-based! France Telecom ECR power measurements on 2 IP routers 15

16 Influence of load on power rating IP routers Still, interesting to have an idea about power consumption, based on load (=throughput) instead of capacity (i.e., shift from circuit-switched to packet-switched approach) How can we take into account actual load (=throughput)? Use ECR (W/Gbps at maximum load) and ECRVL (W/Gbps at variable load), Correction Factor = ECRVL / ECR Measurements results (2 IP routers): about 2.5x worse power rating Example: average throughput: 30 Gbps equipment (capacity-rated): 10 W/Gbps Power: 2.5 x 30 x 10 = 750 Watt (instead of 300 Watt) ECR: 16

17 Power (%) Influence of load on power rating OLAs How does the power in Optical Line Amplifier (sites) scale with the number of active channels? Based on measurements: 100% 90% 111 W 117 W 80 channels active 80% 70% 22 W 121 W 24 W 60% 50% 19 W 40% 1 bidirectional amplifier + overhead 8 channels active 30% 1 unidirectional amplifier 20% 10% 8 ch. 44 ch. 80 ch. 0% 0% 25% 50% 75% 100% Active channels (100% corresponds to 80 channels) France Telecom ECR power measurements on OLA 17

18 Conclusions If using power ratings real-life deployment corrections are important Especially for IP routers (near to 2x worse efficiencies) Especially since corrections are different for different equipment ( relation changes, e.g. IP becomes more dominating than transponders) Caveat: Average lifetime and filling rate assumptions are important. Any lessons for better energy efficiency? Put more power in incremental parts (line cards) and less in common parts (chassis) 18

19 Questions? Ward Van Heddeghem

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