Energy Consumption in IP Networks

Transcription

1 Energy Consumption in IP Networks Rodney S. Tucker, Jayant Baliga, Robert Ayre, Kerry Hinton, Wayne V. Sorin ARC Special Research Centre for Ultra-Broadband Information Networks (CUBIN) University of Melbourne

2 Energy Consumption of the Network Hot spot Why should we be interested in energy? OPEX Greenhouse Impact Managing Hot Spots - Getting the energy in - Getting the heat out Energy-limited capacity bottlenecks Enabling energy efficiencies in other sectors Power In

3 Where are We Heading? More users More data-intensive applications, e.g. video More often and for longer periods Increasing demand operators provide faster access and increased core capacity New applications enabled by faster access Energy Consumption Grows

4 Summary Modeling energy consumption of the Internet - Core, metro, and access networks Energy in network routers Energy in optical transmission Will (can) optical switching technologies help to reduce energy consumption?

5 What is the Carbon Footprint of Telecoms? Global Telecoms Footprint (devices & infrastructure) Fixed Narrowband Mobile Network Mobile handsets X increase 145+% growth Footprint (MtCO 2 p.a.) Broadband Fixed Broadband Modems Adapted from SMART 22: Enabling the low carbon economy in the information age, GeSI, 28

6 Energy Model of Simple IP Network CRS-1 ~ 1 kw / rack Packet over Sonet Edge ~ 4 kw Fibre Amps Core Core Edge Core WDM Core Edge Core Core Core Metro Passive Optical Network OLT - 1W OLT - 1W Curb Curb Curb Curb Access ONU ~ 5-1W Baliga et al., Mb/s to the user

7 Number of Hops in the Internet.1 26 Data Pr [ H = k] AT&T: 2 hops Number of Hops, k Source: P. Van Mieghem, Performance Analysis of Computer Systems and Networks, Cambridge (26)

8 Power Consumption of IP Network 25 2 router hops 27 Technology 2 Contention ratio = Power (W/user) Today s Internet (~ 2.5 Mb/s) Total Routers Access (PON) SDH/WDM Links.5 % of Electricity Supply Peak Access Rate (Mb/s) Baliga et al., 27

9 Ultra-Broadband Access router hops 27 Technology Power (W/user) 5 Contention ratio = 25 Total Access (PON) Routers SDH/WDM 2.5 % of Electricity Supply 1 5 Peak Access Rate (Mb/s) Baliga et al., 27

10 Technology Improvements Total Power Per User (W) Efficiency Improvement Rate = % p.a 5% p.a 1% p.a 2% p.a Peak Access Rate (Mb/s) % of Electricity Consumption Baliga, et al, 28, unpublished

11 Energy Consumption in Access Networks Access N/W Cabinet NEC CM771T Edge Node Splitter PON Cisco NEC CM77S Cabinet NEC VF2F6 FTTN with VDSL2 Cisco 453 Zyxel VES-1616F-34 NEC GM1 PtP Axxcelera ExcelMax CPE Axxcelera ExcelMax BTS WiMAX

12 Power Consumption in Access Networks 4 Oversubscription = 1 25 Power Per User (W) 2 WiMAX PON FTTN PtP Peak Access Rate (Mb/s) Wireless access consumes more energy than optical access PON FTTH is greener than FTTN

13 Network Energy Consumption per Bit Energy per bit (J) 1-3 ~1 μj/b 2 hops ~1 μj/b Total Routers Access (PON) 1-8 WDM Links Peak Access Rate (Mb/s)

14 Observations Optical transport (WDM) consumes relatively little energy < 5% of energy > 25% of CAPEX Access network dominates at low rates Standby/Sleep mode needed Network routers dominate at higher rates Need to reduce hop count improve router efficiency manage distribution and replication of content (IPTV)

15 Power Consumption in Routers 1,, Power consumption (W) 1, 1, 1, 1 1 P ~ 1 P = C 2/3 where P is in Watts where C is in Mb/s 1 nj/bit? 1 nj/bit 1 1 Mb/s 1 Gb/s 1 Tb/s 1 Pb/s Router Throughput Source: METI, 26, Nordman, 27

16 Energy Bottleneck High-end router: Cisco CRS-1 Linecard Chassis Capacity:.64 Tb/s Power: 13.6 kw Switch Fabric Chassis: Power: 8 kw Fully equipped: Multi-rack router Capacity: 41 Tb/s Power ~ 1 MW X2 every 18 months Per Rack Source: Neilsen, 26; Deutche Telekom, 27

17 Electronic Routers Forwarding Engine Fibers J Switch Fabric Demutiplexers O/E Converters Switch Fabrics Buffers Multiplexers Reduced bit rate (i.e. parallel processing) Electronics Optics

18 Energy in Electronic and Optical Routers Line Card I/O O/E O/E Buffer Forwarding Engine Buffer Buffer Forwarding Engine Data Plane Switch Fabric Switch Control Routing Tables Routing Engine Control Plane Power supply inefficiency Fans and blowers Electronic (28) Energy/bit.7 nj 3.2 nj.5 nj 1. nj 1.1 nj 3.5 nj Total 1 nj Electronic (218) 5 pj 65 pj 1 pj 2 pj 25 pj 8 pj 25 pj Optical (218) 65 pj 15 pj? 15 pj 25 pj 8 pj 2 pj Optical Packet Switching is not a promising alternative G. Epps, Cisco, 27, ITRS, 25, R. Tucker, JLT, 26

19 Contention Resolution in the Wavelength Domain λ 1 Forwarding Engine Forwarding Engine Switch Fabric λ n Forwarding Engine Fatal Flaw: Require large n for low blocking probability (n ~3-1 x) Power (W/user) 1 5 Total (Wavelength-domain contention resolution ) Total (Conventional router) Wong, JLT 26 Pathiban et al., JLT 29 Routers 1.2 X Routers WDM 5 X 5 1 Peak Access Rate (Mb/s) Access WDM

20 The Challenge 1 % - 2 % p.a. continuous improvement in efficiency Total Power Per User (W) Efficiency Improvement Rate = % p.a Target 5% p.a 1% p.a 2% p.a Peak Access Rate (Mb/s) % of Electricity Consumption Baliga, et al, 28, unpublished

21 Summary Energy consumption currently dominated by the access network The energy bottleneck in routers is looming - More significant than the so-called electronic speed bottleneck Key strategies for efficient network design - Control energy in the access network (e.g. sleep mode in modems) - Reduce the hop count (i.e. agile optical bypass) - Caching and content distribution networks - Continuous improvement in router efficiency