The administrators of data center networks have to continually monitor path latency to detect network anomaly quickly and ensure the efficient operation of the networks. In this work, we propose Link Layer Measurement...The administrators of data center networks have to continually monitor path latency to detect network anomaly quickly and ensure the efficient operation of the networks. In this work, we propose Link Layer Measurement Protocol （LLMP）, a prototype latency measuring framework based on the Link Layer Discovery Protocol （LLDP）. LLDP is utilized by the controller to discover network topology dynamically. We insert timestamps into the optional LLDPTLV field in LLDP, so that the controller can estimate latency on any single link. The framework utilizes a reactive measurement approach without injecting any probe packets to the network. Our experiments show that the latency of a link can be measured accurately by LLMP. In relatively complex network conditions, LLMP can still maintain a high accuracy. We store the LLMP measurement results into a latency matrix, which can be used to infer the path latency.展开更多
软件定义网络(software defined networking,SDN)架构的三大基本特性成为了网络故障发生的主要影响因素,从而引入新的故障威胁和风险,降低网络可靠性。首先,介绍了SDN的基本架构及其三大基本特性可能引发的安全问题;其次,从架构的物理...软件定义网络(software defined networking,SDN)架构的三大基本特性成为了网络故障发生的主要影响因素,从而引入新的故障威胁和风险,降低网络可靠性。首先,介绍了SDN的基本架构及其三大基本特性可能引发的安全问题;其次,从架构的物理角度出发,分别探讨控制平面域、控制通道域和数据平面域所面临的故障风险;随后,基于各故障域的故障类型,探讨现有的解决方案;最后,对未来的研究工作进行了展望。展开更多
为解决软件定义无人机自组网路由维护存在的控制开销和数据包延迟偏大的问题,基于现有的OpenFlow协议提出了一种高效自适应的软件定义无人机自组网路由维护机制(Efficient and Adaptive Software-defined Unmanned Aerial Vehicle Ad Ho...为解决软件定义无人机自组网路由维护存在的控制开销和数据包延迟偏大的问题,基于现有的OpenFlow协议提出了一种高效自适应的软件定义无人机自组网路由维护机制(Efficient and Adaptive Software-defined Unmanned Aerial Vehicle Ad Hoc Network Routing Maintenance Mechanism Based on OpenFlow Protocol,OpenFlow-EARM)。新机制采用基于距离估计的自适应转发策略,根据无人机节点的历史流表项信息估算并选择时延最低的方式转发流表项缺失数据包,降低数据包传输时延;同时在路由维护过程中采用了基于周期恢复的消息聚合策略,减少控制包的发包次数,从而降低网络控制开销。仿真结果表明,新机制的平均端到端时延、网络控制开销和丢包率等方面性能优于现有的最优化链路状态路由(Optimal Link State Routing,OLSR)协议和OpenFlow协议。展开更多
基金This work was supported by the National Natural Science Foundation of China under Grant Nos. 61379145, 61501482, 61762033.
文摘The administrators of data center networks have to continually monitor path latency to detect network anomaly quickly and ensure the efficient operation of the networks. In this work, we propose Link Layer Measurement Protocol （LLMP）, a prototype latency measuring framework based on the Link Layer Discovery Protocol （LLDP）. LLDP is utilized by the controller to discover network topology dynamically. We insert timestamps into the optional LLDPTLV field in LLDP, so that the controller can estimate latency on any single link. The framework utilizes a reactive measurement approach without injecting any probe packets to the network. Our experiments show that the latency of a link can be measured accurately by LLMP. In relatively complex network conditions, LLMP can still maintain a high accuracy. We store the LLMP measurement results into a latency matrix, which can be used to infer the path latency.
文摘软件定义网络(software defined networking,SDN)架构的三大基本特性成为了网络故障发生的主要影响因素,从而引入新的故障威胁和风险,降低网络可靠性。首先,介绍了SDN的基本架构及其三大基本特性可能引发的安全问题;其次,从架构的物理角度出发,分别探讨控制平面域、控制通道域和数据平面域所面临的故障风险;随后,基于各故障域的故障类型,探讨现有的解决方案;最后,对未来的研究工作进行了展望。
文摘为解决软件定义无人机自组网路由维护存在的控制开销和数据包延迟偏大的问题,基于现有的OpenFlow协议提出了一种高效自适应的软件定义无人机自组网路由维护机制(Efficient and Adaptive Software-defined Unmanned Aerial Vehicle Ad Hoc Network Routing Maintenance Mechanism Based on OpenFlow Protocol,OpenFlow-EARM)。新机制采用基于距离估计的自适应转发策略,根据无人机节点的历史流表项信息估算并选择时延最低的方式转发流表项缺失数据包,降低数据包传输时延;同时在路由维护过程中采用了基于周期恢复的消息聚合策略,减少控制包的发包次数,从而降低网络控制开销。仿真结果表明,新机制的平均端到端时延、网络控制开销和丢包率等方面性能优于现有的最优化链路状态路由(Optimal Link State Routing,OLSR)协议和OpenFlow协议。
