Study On The Algorithms Of Routing And Controller Load Balancing In Multi-domains Software Defined Network

The new services reply generating lead to subscribers has higher capacity requirements for networks.The depended transmission and controlling plane,intelligentize are trend of development for networks.The software defined networks(SDN)is novel network structure based on Open Flow which supports depended transmission and controlling plane.The depended controlling plane can realizes flexible networks flow controlling to achieve intelligentized networks.Comparing with traditional networks,a lot of obvious advantages are gained by SDN which is a revolutionary breakthrough.SDN can complete the tasks that are hard to complete by traditional networks.There are some important points,such as the SDN completely realizes service-aware networks not connection oriented,SDN makes networks development faster than Internet services development.When the new services deploy in SDN,we can complete it by designed software and don't needs to revise the networks protocols.It is improves networks flexible.In other hand,the networks maintainer are liberated by a concentrated controlling plane on logical layer,that means the maintainer don't need to manually configure networks equipment one by one,who just maintains networks on controlling plane by software.This maintains method is lower mistake rate and higher efficiency.With the SDN development,the SDN scale will be enlarged in two conditions:(1)network scale is enlarged by single-domain network become multi-domain network;(2)the larger network scale needs multi-controller in single-domain.In these conditions,two problems wait to solve in SDN,which are multi-domain network routing and multi-controller load balancing.In this thesis,we study on these two problems.For multi-domain network routing problem,we propose a layering based multi-domains routing algorithm(LBMR).The multi-domain network routing can be divided to intra-domain routing and extra-domain routing by LBMR based on topology abstraction.Firstly,the algorithm completes intra-domain routing in multi-domains,then to complete the extra-domain in single domain which belong routing path.In simulation based on OMNet++ software,the results prove the LBMR is useful and has better performance than Dijkstra algorithm.For multi-controller load balancing problem,we propose a service QoS-aware controllers load balancing algorithm.This algorithm can guarantee service Qo S,especially latency,and improve the network's resource utilization.In the load balancing process,we line up the controller according by load condition.Algorithm calculates the latency from lowest load controller.If the latency requirement is satisfied,the switch will be connected with this controller.In simulation based on OMNet++ software,the results prove this algorithm can guarantee service Qo S and improve resource utilization..