Dynamic and Adaptive Load Balancing (DALB) and Controller Adaption and Migration Decision (CAMD) frameworks are the recently developed efficient controller selection frameworks that solved the challenge of load-imbalance in Software-Defined Networking (SDN). While CAMD framework was established to be efficient over DALB framework yet it was not efficient when the incoming-traffic load was elephant flow, hence, leading to a significant reduction in the overall system performance. This study had proposed an Improved Switch Migration Decision Algorithm (ISMDA) that solved the network challenge when the incoming load is elephant flow. The balancing module of the switch migration framework, which runs on each controller, is initiated during the controller load imbalance phase. The improved framework used the controller variance and controller average load status to determine the set of underloaded controllers in the network. The constructed efficient migration model was used to, simultaneously, identify both the migration cost and load-balancing variation for the optimal selection of controller among the set of underloaded controllers. The controller throughput, response time, number of migration space and packet loss were used as the performance comparison metrics. The average controller throughput of ISMDA increased with 7.4% over CAMD framework while average response time of the proposed algorithm improved over CAMD framework with 5.7%. Similarly, the proposed framework had 5.6% average improved migration space over CAMD framework and the packet-loss of ISMDA had average 6.4% performance over the CAMD framework. It was concluded that ISMDA was efficient over CAMD framework when the incoming traffic load is elephant flow.

中文翻译：

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SDN负载均衡的改进交换机迁移决策算法

动态和自适应负载平衡（DALB）以及控制器适应和迁移决策（CAMD）框架是最近开发的高效控制器选择框架，解决了软件定义网络（SDN）中负载不平衡的挑战。虽然CAMD框架被认为比DALB框架更有效，但是当传入的交通负载为大象流量时却效率不高，因此导致整体系统性能显着降低。这项研究提出了一种改进的交换机迁移决策算法（ISMDA），该算法解决了当输入负载为大象流时的网络挑战。在控制器负载不平衡阶段启动在每个控制器上运行的交换机迁移框架的平衡模块。改进的框架使用控制器差异和控制器平均负载状态来确定网络中欠负载控制器的集合。所构建的高效迁移模型用于同时识别迁移成本和负载平衡变化，以便在欠负载控制器组中最佳选择控制器。控制器的吞吐量，响应时间，迁移空间的数量和数据包丢失被用作性能比较指标。与CAMD框架相比，ISMDA的平均控制器吞吐量提高了7.4％，而与CAMD框架相比，所提出算法的平均响应时间提高了5.7％。同样，拟议框架的迁移空间比CAMD框架平均提高了5.6％，ISMDA的数据包丢失性能比CAMD框架平均提高了6.4％。