Abstract: Switch migrations can eliminate overcommitted controllers in Software-Defined Networking(SDN). This paper explores this problem based on game theory. Envision the scenario that a switch managed by a heavy controller is to be migrated into one of its neighbors. Then these two controllers have to compete for this switch to decide whether this switch is migrated. The main contributions are as follows. Firstly, it models this competition by a two-person non-cooperative game theory. Each player independently picks its strategy at the same time. With proper payoff function design, there is a pure strategy Nash equilibrium. Secondly, it designs an Overloaded Controller Eliminated Algorithm（OCEA） based on non-cooperative game. Since different games are played independently, it organizes OCEA in a synthesizing decentralized way.  Finally, with the proof-of-concept implementation, GAME-SM, the results are corroborated based on a real network topology.

Key words: Software-Defined Networking（SDN）, elastic control, game theory, switch migration

摘要： 交换机在不同控制域之间迁移可以消除软件定义网络（SDN）中过载的控制器，过载控制器将部分交换机迁移到其邻居域需要判断迁移哪些交换机及目标控制器。首先将源目的控制器间的交互关系建模为两人非合作博弈，每个博弈参与者独立地选择策略并同时发布，通过设计合理的支付函数，该博弈存在纯策略纳什均衡。设计了一种基于非合作博弈的过载控制器消除算法(Overloaded Controller Eliminated Algorithm，OCEA)，由于不同的博弈活动之间是独立进行的，因此OCEA可以合成为一种分布式的方法。最后，通过原型实现了GAME-SM，验证了算法的有效性。

关键词: 软件定义网络, 弹性控制, 博弈理论, 交换机迁移