Amaru: plug&play resilient in-band control for SDN

Software-Defined Networking (SDN) is a pillar of next-generation networks. ImplementingSDN requires the establishment of a decoupled control communication, which might be installed either as anout-of-band or in-band network. While the benefits of in-band control networks seem apparent, no standardprotocol exists and most of setups are based on ad-hoc solutions. This article defines Amaru, a protocolthat provides plug&play resilient in-band control for SDN with low-complexity and high scalability. Amarufollows an exploration mechanism to find all possible paths between the controller and any node of thenetwork, which drastically reduces convergence time and exchanged messages, while increasing robustness.Routing is based on masked MAC addresses, which also simplifies routing tables, minimizing the numberof entries to one per path, independently of the network size. We evaluated Amaru with three differentimplementations and diverse types of networks and failures, and obtained excellent results, providing almoston-the-fly rerouting and low recovery time.Comunidad de MadridUniversidad de Alcal

Fast Failure Detection of OpenFlow Channels

AINTEC’15 November 18–20, 2015, Bangkok, Thailand.We propose a mechanism to detect OpenFlow channel fail- ures quickly in switches and controllers where multiple con- trollers are running. In OpenFlow networks, it is impor- tant to maintain OpenFlow channels between controllers and switches are up and to detect channel failures immediately, so that messages to notify events such as port down and mod- ification of flow tables are always delivered to the other side surely and quickly. Exchanging keep-alive messages fre- quently is undesirable for controllers because the controllers should handle many keep-alive messages from switches. This would be a significant overhead when the rate of other mes- sages than keep-alive ones is low, because the controllers are forced to handle many keep-alive messages although such keep-alive messages do not affect network control directly. Our proposed mechanism adaptively sends keep-alive mes- sages to detect quickly that a message is not reached to the other side, instead of checking whether a channel is up. A controller shares a message received from a switch with other controllers in a timely manner, and the controller regards a channel has been unavailable if the message notified by other controllers has not arrived via the channel. A switch sends keep-alive messages to all channels just after sending an im- portant asynchronous message such as a port status message, and regards all channels have been gone down if the switch does not receive any response. The evaluation shows that our proposed mechanism reduces failure detection delay to timeout until receiving a response, and that overhead on la- tency is negligible

OpenFlowネットワークにおけるコントロールプレーンの安定性と頑健性

Chapter 4 of this thesis is a minor revision of the work published in "Daisuke Kotani and Yasuo Okabe, Fast Failure Detection of OpenFlow Channels, The 11th Asian Internet Engineering Conference (AINTEC 2015), pp.32-39, November 2015. http://dx.doi.org/10.1145/2837030.2837035" © ACM 2015.京都大学0048新制・課程博士博士(情報学)甲第19847号情博第598号新制||情||104(附属図書館)32883京都大学大学院情報学研究科知能情報学専攻(主査)教授 岡部 寿男, 教授 美濃 導彦, 教授 喜多 一学位規則第4条第1項該当Doctor of InformaticsKyoto UniversityDFA