近幾年，由於網際網路的快速發展以及網路流量的急遽增加，能源消耗對於全世界許多網路服務供應商已成為一個勢不可擋的重要議題。軟體定義網路（Software Defined Network, SDN）為近幾年快速成長的新穎網路架構，SDN 可以有效率的使用網路資源以及達到控制能源消耗的目的。但是，大部分研究對於SDN用於節省能源的應用，鮮少考慮到頻繁的OpenFlow的訊息交換所產生的負擔，而因為多數的網路交換器的CPU有限，因此往往容易造成SDN網路架構的效能降低。本篇論文提出能源感知路由的方法，在SDN的架構下，有效率的減少網路設備所使用的端口數量進而達到能源節省的目的，以及減少端口的開關狀態進而減少頻繁的OpenFlow的訊息交換。此外，本篇論文也考慮到網路流量的負載平衡以及能源消耗兩者之間的調整平衡。我們將能源消耗問題轉化成為線性規劃（Integer Linear Programming, ILP）方程式並提出一個新穎的演算法，即有效率地降低能源消耗以及低負擔的能源感知路由（Time Efficient and Low-overhead Energy-Aware Routing, TELEAR）。本篇實驗顯示，TELEAR 比現有的感知路由方法更為有效率以及有較低的OpenFlow訊息交換所產生的負擔。

Due to the rapid development of Internet and the increasing traffic load, power consumption becomes a critical issue for many network service providers around the world. The emerging technology, Software Defined Networking (SDN), can adaptively manage the network resources and control the power consumption. However, most previous studies for energy saving seldom consider the control overhead of OpenFlow operation due to the limitation of OpenFlow switch's CPU when applying SDN. In this paper, a novel algorithm in SDN enabled networks is investigated. The aim is to reduce the number of used links and the number of link state changes in a time efficient way so that the energy consumption and the control overhead of OpenFlow switches can be decreased respectively. Moreover, how to balance energy saving and congestion of traffic is also considered in this paper. Specifically, the energy consumption problem, which is NP-hard, for routing traffic in a network is formulated as an Integer Linear Programming (ILP) problem. A Time Efficient and Low-overhead Energy-Aware Routing (TELEAR) algorithm is proposed to dynamically route flows in a time efficient manner. The evaluation results show that TELEAR not only outperforms the other schemes in terms of computation time and the control overhead of OpenFlow switches but also achieves better energy saving.

[1] L. Chiaraviglio, M. Mellia, and F. Neri, “Minimizing ISP Network Energy Cost: Formulation and
Solutions,” IEEE/ACM Transactions on Networking, pp. 463–476, Apr. 2012.
[2] R. F. e Silva and P. M. Carpenter, “Energy Efficient Ethernet on Mapreduce Clusters: Packet Coalescing
To Improve 10 GbE Links,” IEEE/ACM Transactions on Networking, vol. 25, pp. 2731–2742,
Oct. 2017.
[3] J. Chabarek, J. Sommers, P. Barford, C. Estan, D. Tsiang, and S. Wright, “Power Awareness in
Network Design and Routing,” in Proceedings of IEEE INFOCOM, pp. 457–465, Apr. 2008.
[4] P. Mahadevan, P. Sharma, S. Banerjee, and P. Ranganathan, “A Power Benchmarking Framework for
Network Devices,” in 8th International IFIP-TC Networking Conference, pp. 795–808, 2009.
[5] F. Giroire, J. Moulierac, and T. K. Phan, “Optimizing Rule Placement in Software-Defined Networks
for Energy-aware Routing,” in IEEE Global Communications Conference, pp. 2523–2529, Dec. 2014.
[6] N. McKeown, T. Anderson, H. Balakrishnan, G. Parulkar, L. Peterson, J. Rexford, S. Shenker, and
J. Turner, “OpenFlow: Enabling Innovation in Campus Networks,” SIGCOMM Comput. Commun.
Rev., vol. 38, pp. 69–74, Mar. 2008.
[7] M. Kobayashi, S. Seetharaman, G. Parulkar, G. Appenzeller, J. Little, J. Van Reijendam, P. Weissmann,
and N. McKeown, “Maturing of OpenFlow and Software-Defined Networking through Deployments,”
Computer Networks, vol. 61, pp. 151–175, Mar. 2014.
[8] J. C. Mogul, J. Tourrilhes, P. Yalagandula, P. Sharma, A. R. Curtis, and S. Banerjee, “DevoFlow:
Cost-effective Flow Management for High Performance Enterprise Networks,” in Proceedings of the
9th ACM SIGCOMM Workshop on Hot Topics in Networks, pp. 1–6, Oct. 2010.
[9] S. Orlowski, M. Pi´oro, A. Tomaszewski, and R. Wess¨aly, “SNDlib 1.0–Survivable Network Design
Library,” in Proceedings of the 3rd International Network Optimization Conference, Apr. 2007.
[10] M. Webb et al., “SMART 2020: Enabling the Low Carbon Economy in the Information Age,” The
Climate Group. London, vol. 1, no. 1, pp. 1–1, 2008.
[11] V. Mathew, R. K. Sitaraman, and P. Shenoy, “Energy-Aware Load Balancing in Content Delivery
Networks,” in Proceedings of IEEE INFOCOM, pp. 954–962, Mar. 2012.
[12] S. Alanazi, M. Dabbagh, B. Hamdaoui, M. Guizani, and N. Zorba, “Reducing Data Center Energy
Consumption Through Peak Shaving and Locked-In Energy Avoidance,” IEEE Transactions on Green
Communications and Networking, vol. 1, pp. 551–562, Dec. 2017.
[13] Y. Li, A. C. Orgerie, and J. M. Menaud, “Balancing the Use of Batteries and Opportunistic Scheduling
Policies for Maximizing Renewable Energy Consumption in a Cloud Data Center,” in Euromicro
32
International Conference on Parallel, Distributed and Network-based Processing (PDP), pp. 408–
415, Mar. 2017.
[14] Y. Tarutani, Y. Ohsita, and M. Murata, “Virtual Network Reconfiguration for Reducing Energy Consumption
in Optical Data Centers,” IEEE/OSA Journal of Optical Communications and Networking,
vol. 6, pp. 925–942, Oct. 2014.
[15] P. Duan, K. Wang, X. Yu, L. Liu, H. Gu, and Y. Guo, “Flow Driven Energy-Aware Routing Algorithm
in Data Center Network,” in International Conference on Parallel and Distributed Computing,
Applications and Technologies (PDCAT), pp. 280–285, Dec. 2016.
[16] H. Lin, M. Xu, and Y. Yang, “Robust Energy-Aware Routing with Uncertain Traffic Demands,” in
International Conference on Computer Communication and Networks (ICCCN), pp. 1–8, Aug. 2015.
[17] A. Khreishah, H. B. Salameh, I. Khalil, and A. Gharaibeh, “Renewable Energy-Aware Joint Caching
and Routing for Green Communication Networks,” IEEE Systems Journal, pp. 1–10, 2016.
[18] S. S. W. Lee and K. Y. Li, “Study of Dynamic Topology Change for Total Energy Consumption in
Green IP Networks,” in IEEE International Conference on Green Computing and Communications
and IEEE Internet of Things and IEEE Cyber, Physical and Social Computing, pp. 64–70, Aug. 2013.
[19] D. Li, Y. Yu, J. Shi, and B. Zhang, “PALS: Saving Network Power With Low Overhead to ISPs and
Applications,” IEEE/ACM Transactions on Networking, vol. 24, pp. 2913–2925, Oct. 2016.
[20] Y. Shang, D. Li, and M. Xu, “Greening Data Center Networks with Flow Preemption and Energyaware
Routing,” in IEEE Workshop on Local Metropolitan Area Networks (LANMAN), pp. 1–6, Apr.
2013.
[21] R. Bolla, R. Bruschi, F. Davoli, and C. Lombardo, “Fine-Grained Energy-Efficient Consolidation
in SDN Networks and Devices,” IEEE Transactions on Network and Service Management, vol. 12,
pp. 132–145, Jun. 2015.
[22] X. Meng, L. Zheng, L. Li, and J. Li, “PAM: An Efficient Power-Aware Multi-level Cache Policy to
Reduce Energy Consumption of Software Defined Network,” in International Conference on Industrial
Networks and Intelligent Systems (INISCom), pp. 18–23, Mar. 2015.
[23] G. Portaluri, D. Adami, A. Gabbrielli, S. Giordano, and M. Pagano, “Power Consumption-Aware
Virtual Machine Placement in Cloud Data Center,” IEEE Transactions on Green Communications
and Networking, vol. 1, pp. 541–550, Dec. 2017.
[24] M. R. Celenlioglu, S. B. Goger, and H. A. Mantar, “An SDN-based Energy-Aware Routing Model for
Intra-Domain Networks,” in International Conference on Software, Telecommunications and Computer
Networks (SoftCOM), pp. 61–66, Sep. 2014.
[25] H. Li, G. Jiang, and R. Chai, “Energy Consumption Optimization Based Joint Routing and Flow
Allocation Algorithm for Software Defined Networking,” in International Symposium on Wireless
Personal Multimedia Communications (WPMC), pp. 311–316, Nov. 2016.
33
[26] M. N. Siraj, N. Javaid, Q. Shafi, Z. Ahmed, U. Qasim, and Z. A. Khan, “Energy Aware Dynamic Routing
Using SDN for a Campus Network,” in International Conference on Network-Based Information
Systems (NBiS), pp. 226–230, Sep. 2016.
[27] A. Amokrane, R. Langar, R. Boutaba, and G. Pujolle, “Flow-Based Management For Energy Efficient
Campus Networks,” IEEE Transactions on Network and Service Management, vol. 12, pp. 565–579,
Dec. 2015.
[28] F. Giroire, D. Mazauric, J. Moulierac, and B. Onfroy, “Minimizing Routing Energy Consumption:
from Theoretical to Practical Results,” in IEEE Green Computing and Communications (GreenCom),
pp. 252–259, Dec. 2010.
[29] X. Wang, Y. Yao, X. Wang, K. Lu, and Q. Cao, “CARPO: Correlation-Aware Power Optimization in
Data Center Networks,” in Proceedings of IEEE INFOCOM, pp. 1125–1133, Mar. 2012.
[30] T. M. Nam, N. H. Thanh, N. Q. Thu, H. T. Hieu, and S. Covaci, “Energy-Aware Routing based on
Power Profile of Devices in Data Center Networks using SDN,” in International Conference on Electrical
Engineering/Electronics, Computer, Telecommunications and Information Technology (ECTICON),
pp. 1–6, Jun. 2015.