Design And Implementation Of QoS System Based On Openflow

With the rapid development of real-time media application such as IPtelephonyand videoconferencing in the field of Internet, which raised QoSrequirement of transmission that only afford best effort on the network.While existing QoS systems implemented based on IntServ or DiffServmodel have some shortcomings such as deployed at a high cost, requiringhardware support, lack of automatic configuration and the challenge forfinding a global optimal routing path. To solve the mentioned problems,we describle an architecture to support QoS flows based on OpenFlow byusing its programmability, scalability, enhanced network management andcontrol features.The main work of this paper include the following aspects:1) Obtainthe entire network status information by using OpenFlow protocol, monitorand schedule the QoS flows better, fast response towarning and fault suchas link failure, support both automation and using application toconfigurethe QoS system in real time, simplified configuration and management,2)Monitor the flow in the network that require substantial bandwidth byusing flow demand estimation algorithm, optimal path schedule, select theglobal optimal path for QoS flow based on the bandwidth of link, thelength of path and priority of flow to improving the reliability andtransmission time for QoS flows,3)verify the QoS flow based on thefunction of admission control, clear all the flow-table in switches and thenrewrite it to ensure the QoS level in congested network.The system was implemented based on POX controller. Theexperiments based on Mininet environment proved the correctness of thesystem function, indicated that the QoS flow can be transmitted with priority and reliability.