Design And Implementation Of QoS System Of Virtual Network In OpenDaylight

SDN(Software Defined Network)network completely subverted the com?plexity situation in traditional IP network,in data link layers,equipment manu-farturers and transmission protocols.In principle,SDN can be a good solution to the traditional network problem.QoS(Quality of Service,QoS)system measures and guarantees the net-work quality of users by means of bandwidth,delay,jitter and other indicators.In the traditional network,there is no centralized control function.Most of the QoS technologies are implemented by the way of patching.It is difficult to effectively carry out systematic service quality assurance.The centralized con-trol idea of SDN network provides the possibility for QoS to implement in SDN network.At present,there is no systematic QoS implementation scheme in SDN network.Considering the characteristics of centralized control and virtualiza-tion of SDN network,a set of QoS control system on the VTN(Virtual Tenant Network,tenant virtual network)module of the ODL(OpenDaylight)controller is implemented in this paper.The system uses the DiffServ differential service model strategy proposed by the IETF(The Internet Engineering Task Force,the international Internet Engineering Task Force)as the algorithm,and uses the IP address,port and protocol as the matching field to distinguish the ser-vice types of the data flow,and set the DSCP(DiffServ Code Point,differential service code)values.Through the switch port queue configuration,it provides different network resources for different network services according to the pa-rameters of bandwidth,priority and delay.It avoids the problem of network instability and network resource waste caused by the preemption of resources,and provides a high quality network environment for network services which need more network resources.This article uses Tomcat as the JAVA Web server,HTTP requests and pro-cessing through Servlet and AJAX,and the complete implementation of the QoS system using the differential service model from the front end to the back-ground.At the same time,the system modified the source code of the ODL controller,completed the function of time delay measurement and rate mea-surement,obtained the network delay and rate,and took it as an important pa-rameter of the QoS system.The path selection test,queue configuration test and multi flow comparison test are carried out in this paper.The experimental results show that the system can effectively improve the performance of DSN network on bandwidth occupancy,delay and jitter.The feasibility of QoS con-trol system under complex network demand is verified.