Design And Implementation Of A Network Load Balancing Scheme Based On SDN

Load balancing is one of the solutions to ensure network quality of service, it is mainly to expand the network through the rational management of the network and computing resources, thus avoiding network congestion and improve network performance and robustness. When the software-defined network architectures emerge, how to use OpenFlow protocol, combining centralized control and software-programmable which is the feature of SDN, design and implementation of network load balancing strategy, remains to be studied and improved. Compared with traditional network architectures, using SDN to deploy network load balancing scheme has the following advantages:(1) SDN can be used to achieve network load balancing with software in the controller layer, does not require special hardware.(2) SDN easier access to a global network compared to traditional network topologies, easier to develop global optimal strategy.(3) SDN switch devices can be centrally controlled and configured by the controller, rather than individually configure the switch.Based on the above background, the main work of this paper is to design and implement a network load balancing solution based on SDN with the purpose of taking advantage of software-defined network, to design a flexible and effective network load balancing mechanism. Network load balancing involves the link load balancing and application layer load balancing, therefore this paper will be discussed from the following three aspects:(1)Design and implement a link load balancing solution. With the help of the centralized control feature of SDN, we can obtain a global network topology by periodically sending the relevant protocol packets, and then based on this paper implements an optimal k path algorithm to select the optimal k of redundancy link, and finally we have developed evaluation model to assess all the links which are candidate link to obtain the most favorable current global network link load balancing, and finally deploy the corresponding forwarding strategy to flow table in OpenFlow switch.(2)Design and implement an application-layer load balancing solution. Because the habits and network state of different users for the same kind of network service requests are difference. So we can collect a series of data from the user layer, including frequent of the service requests, the network delays and the rate of lost packet and other parameters. These parameters will be sent to an intermediate server to calculate the current priority of users. The controller provides different forwarding policies based on user priorities. The final effect is allocating on-demand services resources to different users.(3)In order to detect our network load balancing solution, but also to provide more convenient network monitoring tools for network administrator, this paper also includes three visualization works:visualizing the overall network topology, link status, and user data collection.