1. BalanceFlow: Controller load balancing for OpenFlow networks Hu, Yannan ; Wang, Wendong ; Gong, Xiangyang ; Que, Xirong ; Cheng, Shiduan Cloud Computing and Intelligent Systems (CCIS), 2012 IEEE 2nd International Conference on 1

2. Outline Introduction – Controller may be bottleneck in OpenFlow – Existd solution System architecture Simulated results Conclusion Reference 2

3. Controller may be bottleneck in OpenFlow If a OpenFlow switch get a packet which does not match the flow table, OpenFlow switch will send the packet to controller. 3

4. Controller may be bottleneck in OpenFlow 4

5. Existd mechanism- OpenFlow 1.2 OpenFlow 1.2 supports multiple controller connection for one switch. – Each controller may send a OFPT_ROLE_REQUEST message to communicate its role to the switch OFPCR_ROLE_MASTER OFPCR_ROLE_SLAVE – But there is not any mechanism for the communication and flow-request load balancing. 5

6. System architecture BalanceFlow 6

7. Controller’s job Each controller k maintains an N × N matrix M k, where N is the number of switches in the network. The element in the ith row, jth column denotes the average number of flow-requests from switch i to switch j. The super controller is responsible for collecting the flow-requests matrixes published by all controllers. 7

8. Detecting imbalance The super controller detects controller load imbalance when the average number of flow- requests handled by any controller contributes more than some threshold of the total flow-requests rate in the network. 8

9. Generating allocation information Algorigthm 9 Cost :

10. Simulated results 10

11. Conclusion The super controller runs partition algorithm and reallocates the load of different controller by distributing allocation rules to switches. BalanceFlow can handle controller load balancing entirely at the controller level. 11

12. Reference OpenFlow Switch Specification 1.3.2 - Open Networking Foundation OpenFlow Switch Specification 1.3.2 - Open Networking Foundation 12

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