Through the analysis to the DDoS（distributed denial of service） attack, it will conclude that at different time segments, the arrive rate of normal SYN （Synchronization） package are similar, while the abnormal pac...Through the analysis to the DDoS（distributed denial of service） attack, it will conclude that at different time segments, the arrive rate of normal SYN （Synchronization） package are similar, while the abnormal packages are different with the normal ones. Toward this situation a DDoS defense algorithm based on multi-segment timeout technology is presented, more than one timeout segment are set to control the net flow. Experiment results show that in the case of little flow, multi-segment timeout has the ability dynamic defense, so the system performance is improved and the system has high response rate.展开更多
We consider a single-server vacation queueing system that operates in the following manner. When the server returns from a vacation, it observes the following rule. If there is at least one customer in the system, the...We consider a single-server vacation queueing system that operates in the following manner. When the server returns from a vacation, it observes the following rule. If there is at least one customer in the system, the server commences service and serves exhaustively before taking another vacation. If the server finds the system empty, it waits a fixed time c. At the expiration of this time, the server commences another vacation if no customer has arrived;otherwise, it serves exhaustively before commencing another vacation. Analytical results are derived for the mean waiting time in the system. The timeout scheme is shown to be a generalized scheme of which both the single vacation and multiple vacations schemes are special cases, with c=∞and c=0, respectively. The model is extended to the N-policy vacation queueing system.展开更多
Accurately estimating of Retransmission TimeOut (RTO) in Content-Centric Networking (CCN) is crucial for efficient rate control in end nodes and effective interface ranking in intermediate routers. Toward this end, th...Accurately estimating of Retransmission TimeOut (RTO) in Content-Centric Networking (CCN) is crucial for efficient rate control in end nodes and effective interface ranking in intermediate routers. Toward this end, the Jacobson algorithm, which is an Exponentially Weighted Moving Average (EWMA) on the Round Trip Time (RTT) of previous packets, is a promising scheme. Assigning the lower bound to RTO, determining how an EWMA rapidly adapts to changes, and setting the multiplier of variance RTT have the most impact on the accuracy of this estimator for which several evaluations have been performed to set them in Transmission Control Protocol/Internet Protocol (TCP/IP) networks. However, the performance of this estimator in CCN has not been explored yet, despite CCN having a significant architectural difference with TCP/IP networks. In this study, two new metrics for assessing the performance of RTO estimators in CCN are defined and the performance of the Jacobson algorithm in CCN is evaluated. This evaluation is performed by varying the minimum RTO, EWMA parameters, and multiplier of variance RTT against different content popularity distribution gains. The obtained results are used to reconsider the Jacobson algorithm for accurately estimating RTO in CCN. Comparing the performance of the reconsidered Jacobson estimator with the existing solutions shows that it can estimate RTO simply and more accurately without any additional information or computation overhead.展开更多
Accurate early classification of elephant flows(elephants)is important for network management and resource optimization.Elephant models,mainly based on the byte count of flows,can always achieve high accuracy,but not ...Accurate early classification of elephant flows(elephants)is important for network management and resource optimization.Elephant models,mainly based on the byte count of flows,can always achieve high accuracy,but not in a time-efficient manner.The time efficiency becomes even worse when the flows to be classified are sampled by flow entry timeout over Software-Defined Networks(SDNs)to achieve a better resource efficiency.This paper addresses this situation by combining co-training and Reinforcement Learning(RL)to enable a closed-loop classification approach that divides the entire classification process into episodes,each involving two elephant models.One predicts elephants and is retrained by a selection of flows automatically labeled online by the other.RL is used to formulate a reward function that estimates the values of the possible actions based on the current states of both models and further adjusts the ratio of flows to be labeled in each phase.Extensive evaluation based on real traffic traces shows that the proposed approach can stably predict elephants using the packets received in the first 10% of their lifetime with an accuracy of over 80%,and using only about 10% more control channel bandwidth than the baseline over the evolved SDNs.展开更多
高性能水声路由协议要求协议具有高吞吐量的同时,能耗尽可能小,这是提高能源利用效率的关键.针对这一问题,提出基于能量优化和超时传输的水声传感器网络路由协议.首先,路由寻找阶段融合能量均衡策略并利用退避机制尽可能接收多的路由请...高性能水声路由协议要求协议具有高吞吐量的同时,能耗尽可能小,这是提高能源利用效率的关键.针对这一问题,提出基于能量优化和超时传输的水声传感器网络路由协议.首先,路由寻找阶段融合能量均衡策略并利用退避机制尽可能接收多的路由请求再进行回复来控制路由开销;然后,数据传输阶段引入超时传输机制,利用主备份路由协同传输并监听和判断链路有效性,融合碰撞避免机制规避碰撞;最后,通过仿真和水下实验与按需平面距离向量路由协议(Ad Hoc on-demand distance vector routing,AODV)和矢量转发路由协议(vector based forwarding,VBF)进行对比.仿真实验结果表明:所提出协议相比于AODV与VBF,吞吐量和数据包成功接收率均有提升,且具有更低的单位字节能耗;水下实验结果表明:相比于AODV,所提出协议吞吐量提升了11.84%,数据包成功接收率提升了15.62%,单位字节能耗可降低0.10 J.展开更多
新能源汽车通信环境复杂,控制器局域网(Controller Area Network,CAN)总线通信超时故障频发,影响车辆性能与安全。为此,提出新能源汽车CAN总线通信超时故障检测方法。通过获取CAN总线通信数据,采用分段三次Hermite插值法进行数据拟合,...新能源汽车通信环境复杂,控制器局域网(Controller Area Network,CAN)总线通信超时故障频发,影响车辆性能与安全。为此,提出新能源汽车CAN总线通信超时故障检测方法。通过获取CAN总线通信数据,采用分段三次Hermite插值法进行数据拟合,并对比拟合曲线斜率和预设阈值,检测是否存在故障。实验结果显示,该方法检测平均准确率为95.56%,误报率为2.58%,具有高精度。展开更多
基金Supported by the Natural Science Foundation ofHebei Province (F2004000133)
文摘Through the analysis to the DDoS（distributed denial of service） attack, it will conclude that at different time segments, the arrive rate of normal SYN （Synchronization） package are similar, while the abnormal packages are different with the normal ones. Toward this situation a DDoS defense algorithm based on multi-segment timeout technology is presented, more than one timeout segment are set to control the net flow. Experiment results show that in the case of little flow, multi-segment timeout has the ability dynamic defense, so the system performance is improved and the system has high response rate.
文摘We consider a single-server vacation queueing system that operates in the following manner. When the server returns from a vacation, it observes the following rule. If there is at least one customer in the system, the server commences service and serves exhaustively before taking another vacation. If the server finds the system empty, it waits a fixed time c. At the expiration of this time, the server commences another vacation if no customer has arrived;otherwise, it serves exhaustively before commencing another vacation. Analytical results are derived for the mean waiting time in the system. The timeout scheme is shown to be a generalized scheme of which both the single vacation and multiple vacations schemes are special cases, with c=∞and c=0, respectively. The model is extended to the N-policy vacation queueing system.
文摘Accurately estimating of Retransmission TimeOut (RTO) in Content-Centric Networking (CCN) is crucial for efficient rate control in end nodes and effective interface ranking in intermediate routers. Toward this end, the Jacobson algorithm, which is an Exponentially Weighted Moving Average (EWMA) on the Round Trip Time (RTT) of previous packets, is a promising scheme. Assigning the lower bound to RTO, determining how an EWMA rapidly adapts to changes, and setting the multiplier of variance RTT have the most impact on the accuracy of this estimator for which several evaluations have been performed to set them in Transmission Control Protocol/Internet Protocol (TCP/IP) networks. However, the performance of this estimator in CCN has not been explored yet, despite CCN having a significant architectural difference with TCP/IP networks. In this study, two new metrics for assessing the performance of RTO estimators in CCN are defined and the performance of the Jacobson algorithm in CCN is evaluated. This evaluation is performed by varying the minimum RTO, EWMA parameters, and multiplier of variance RTT against different content popularity distribution gains. The obtained results are used to reconsider the Jacobson algorithm for accurately estimating RTO in CCN. Comparing the performance of the reconsidered Jacobson estimator with the existing solutions shows that it can estimate RTO simply and more accurately without any additional information or computation overhead.
基金supported by the National Natural Science Foundation of China(61962016)the Ministry of Science and Technology of China(G2022033002L)+1 种基金National Natural Science Foundation of Guangxi(2022JJA170057)Guangxi Education Department’s Project on Improving the Basic Research Ability of Young and Middleaged Teachers in Universities(2023ky0812,Research on Statistical Network Delay Predictions in Large-scale SDNs).
文摘Accurate early classification of elephant flows(elephants)is important for network management and resource optimization.Elephant models,mainly based on the byte count of flows,can always achieve high accuracy,but not in a time-efficient manner.The time efficiency becomes even worse when the flows to be classified are sampled by flow entry timeout over Software-Defined Networks(SDNs)to achieve a better resource efficiency.This paper addresses this situation by combining co-training and Reinforcement Learning(RL)to enable a closed-loop classification approach that divides the entire classification process into episodes,each involving two elephant models.One predicts elephants and is retrained by a selection of flows automatically labeled online by the other.RL is used to formulate a reward function that estimates the values of the possible actions based on the current states of both models and further adjusts the ratio of flows to be labeled in each phase.Extensive evaluation based on real traffic traces shows that the proposed approach can stably predict elephants using the packets received in the first 10% of their lifetime with an accuracy of over 80%,and using only about 10% more control channel bandwidth than the baseline over the evolved SDNs.
文摘高性能水声路由协议要求协议具有高吞吐量的同时,能耗尽可能小,这是提高能源利用效率的关键.针对这一问题,提出基于能量优化和超时传输的水声传感器网络路由协议.首先,路由寻找阶段融合能量均衡策略并利用退避机制尽可能接收多的路由请求再进行回复来控制路由开销;然后,数据传输阶段引入超时传输机制,利用主备份路由协同传输并监听和判断链路有效性,融合碰撞避免机制规避碰撞;最后,通过仿真和水下实验与按需平面距离向量路由协议(Ad Hoc on-demand distance vector routing,AODV)和矢量转发路由协议(vector based forwarding,VBF)进行对比.仿真实验结果表明:所提出协议相比于AODV与VBF,吞吐量和数据包成功接收率均有提升,且具有更低的单位字节能耗;水下实验结果表明:相比于AODV,所提出协议吞吐量提升了11.84%,数据包成功接收率提升了15.62%,单位字节能耗可降低0.10 J.
文摘新能源汽车通信环境复杂,控制器局域网(Controller Area Network,CAN)总线通信超时故障频发,影响车辆性能与安全。为此,提出新能源汽车CAN总线通信超时故障检测方法。通过获取CAN总线通信数据,采用分段三次Hermite插值法进行数据拟合,并对比拟合曲线斜率和预设阈值,检测是否存在故障。实验结果显示,该方法检测平均准确率为95.56%,误报率为2.58%,具有高精度。
