The Research And Implementation Of Adaptive QoS Configuration Based On ODL In DMVPN

In modern network,enterprise headquarters or data centers are increasingly using VPN technology to connect unit offices,partner units,and telecommuters.As the world's leading provider of network solution,Cisco recommends using DMVPN technology to solve enterprise headquarters and branch communications or data transmission.QoS can achieve good results in the service level agreement(SLA)environment provided by the ISP.In a non-SLA environment,bandwidth utilization is not high because the available bandwidth on the network link changes at any time,and the actual bandwidth is usually much lower than the bandwidth provided by the ISP.For non-SLA environments in DMVPN network,Cisco has proposed adaptive QoS mechanism to adjust the link rate across the link based on changes in available bandwidth in real time,to take full advantage of bandwidth.But because of limitation of the traditional network technology,this adaptive QoS mechanism did not achieve the desired results in the actual project.With the arrival of the SDN era and ODL,it is a good time for improving the adaptive QoS mechanism.In order to solve the problem of QoS blindness better(can not adjust the QoS policy in real time according to the link change),in order to improve the utilization of bandwidth on the link in non-SLA environment better,and make the packet loss does not occur in the ISP to save unnecessary expenses for enterprises in DMVPN network,this thesis research and implement the adaptive QoS configuration system based on ODL.The main work of this thesis include:(1)The existing adaptive QoS mechanism is improved by combining the SDN architecture and adding DSCP classification and marking in QoS,to solve the problem that the QoS policy needs to be manually configured in the DMVPN network,and the QoS policy can not be adjusted in real time according to the change of link bandwidth,to solve the problem that the transmission delay of the link is relatively large and the information of package is asymmetric in the DMVPN network,to solve the problem that how to detect packet loss in the DMVPN network and discard them on the border router before entering Internet.(2)Based on the adaptive QoS mechanism and ODL controller,an adaptive QoS policy configuration and deployment system is designed and implemented for the development of the southbound protocol plug-in based on the SAL kernel-related services and the upper-layer service port.(3)It evaluates the adaptive QoS configuration system based on ODL from the aspects of function and performance,and demonstrates the rationality and correctness of the improved adaptive QoS mechanism.