An SDNbased Hybrid Strategy for Load Balancing in Data Center Networks th for various services. Yet todayxe2x80x99s widely used load balancing scheme, i.e., ECMP, may cause serious congestion when hash collision happens. Recent proposals either push load balancing function to a centralized controller or network edges. However, the centralized schemes are too slow for latencysensitive flows, while the distributed schemes lack the global view and usually cannot make the best choices. In this paper, based on SoftwareDefined Networking (SDN), we present a new hybrid load balancing scheme called BLEND. It promotes the cooperation among network components and takes advantage of both global view and fast endhost action. BLEND aims to improve the throughput of big flows and reduce the latency of small and medium flows. It employs a controller to assign paths to big flows to achieve high throughput. In addition, in order to provide guidance for fast distributed load balancing decisions, the controller also calculates the optimal network delay thresholds for small and medium flows, while hosts utilize these thresholds to decide whether to change the current paths. BLEND is practical and easily deployable in the current data center networks. Comprehensive experiments demonstrate that BLEND outperforms both the centralized and distributed schemes and achieves at most 40% reduction in FCT and at most 2.8 times improvement in throughput.

SoftwareDefined Networking load distribution technique for an internet service provider Abstract   Internet Service Providers (ISPs) are expected to continuously provide services without interruptions. However, planning for this activity requires a number of tasks such as forecasting clientsu0027 demand that needs to be considered in fulfilling their objectives particularly in face of calamity and traffic load variations. We present a SoftwareDefined Networking (SDN) load distribution technique for a typical ISP. We have implemented an optimization method employing linear programming to achieve this goal. A multiobjective model has been developed for this purpose. The multiple objectives are maximization of link utilization, maximization of link availability and minimization of average roundtrip time for the top visited websites by users. Furthermore, an automated load distribution system has been developed for carrying out these optimization related activities. In addition, an example is presented to illustrate traffic load distribution under different operational modes (normal, critical, and catastrophic). The findings of this study should be of great help to the service provider to better plan for load distribution between international links, and help in approving down times and maintenance windows requested by cable providers.