基于OVS的SDN移动自组网络架构设计及实现

SDN-based MANET Architecture Design and Implementation Based on Extended Open vSwitch

在SDN移动自组网络中,控制转发策略集中于控制器中,使得基于流表匹配的数据转发变得简单高效。但是,由于移动自组网环境复杂多变、无线信号不稳定和网络拓扑多变等原因,容易出现数据层面失去控制器控制和流表学习老化等问题,这严重制约网络性能。针对以上问题,设计了一种基于Open v Switch的SDN移动自组网络架构,架构包含状态处理与应用感知等核心功能。状态处理服务实现控制器与交换机连接状态的跟踪检测、Open Flow协议的状态匹配字段拓展和数据包在不同状态场景下进行感知处理等功能,应用感知服务实现转发策略在数据层面被灵活调度的功能。在Open v Switch和Ryu开源控制器上进行协议开发和原型系统搭建。实验结果表明,控制器连发生接故障后,业务恢复时延低于100 ms,流表项可以及时更新,这可以保障网络吞吐量的稳定性。因此,设计的架构有效减小控制器失连故障对通信的影响,增强了基于SDN的移动自组网络的稳定性和可靠性。

In software-defined mobile ad hoc networks （SDN-based MANET） ,a controller centrally controls the network to keep the data plane simple and efficient. However, due to the complexity and variation of MANET environment, the instability of wireless signal and the continuous changing of network topology,the data plane can＇ t know how to process and forward new packets because of loss of control.Besides,while the topology has changed, a switch will use the old rule incorrectly until the controller inserts/updates the flow table entry.To solve these problems,a new approach of SDN-based MANET architecture based on extended Open vSwiteb （OVS） is introduced,which enables packet-processing of different states and is application-aware in data plane. An implementation of this architecture achieves the tracking of connection state,state match and packet-processing service in data plane.This paper implements this new architecture and evaluates the performance using a prototype implementation based on extended OVS and RYU.The results show that the proposed architecture reduces the recovery time from controller connection loss and keeps rules updating in real-time, which maintains a stable throughput and decreases the effect of controller connection loss.This architecture enhances the reliability and stability of SDN-based mobile ad hoe networks.