Centralized Bandwidth Allocation Algorithm Based On SDN

Software Defined Network decouples network forwarding and network control in a programmable manner and it is now widely used in data center network.The satellite communication network is not flexible for network configuration and cannot provide services to the users on demand.Software Defined Network can solve these problems by separating the data plane from the control plane.Today,most of the applications of software-defined technologies in satellite networks are about the architecture and scene design of software-defined satellite networks.However,few people pay attention to the design of an inter-satellite link path-planning algorithm under this network architecture that can provide users with quality assurance services.Based on the existing software-defined satellite network architecture,this paper studies the centralized bandwidth allocation algorithm in the controller.The research work is divided into the following three parts.Firstly,this paper proposes a bandwidth allocation algorithm based on 0-1 type integer programming.This algorithm defines a common model of user requests and designs a request routing algorithm that is suitable for satellite network scenarios.In addition,this paper also proposes three optimization objectives for different scenario scenarios,which can respectively optimize the overall utilization of network resources,maximize the user service rate and differentiate users' services.Secondly,this paper proposes a bandwidth allocation mechanism based on time reservation.The algorithm can provide bandwidth reservation service for time-scheduled application requests in satellite networks.The algorithm improves the Dijkstra algorithm and proposes a link resource-status updating algorithm,which can fully utilize the network resources under the premise of satisfying user's request.Finally,this paper uses C++ and MATLAB to build a simulation system to simulate the performance of these two centralized bandwidth allocation algorithms based on Software Defined Network.This system can not only randomly generate network topology and user requests,but also calculate the overall network resource utilization and user service rates of each priority users.Under the 20-node network topology generated randomly using Salam code,the utilization of 0-1 integer bandwidth allocation algorithm can make the network utilization rate up to 95%,which is 12%more than the traditional IntServ algorithm.The experimental results show that the bandwidth allocation algorithm based on time reservation can increase the service rate of users by 20%and achieve the fine-grained allocation of resources.The experimental results show that the two proposed algorithms are reliable bandwidth allocation mechanisms for satellite network.