With the evolution of network technologies, the deficiencies of TCP protocol are becoming more and more distinct. The new TCP implementation, called Receiver Advertisement Based TCP (TCP-Rab) proposed here to eliminat...With the evolution of network technologies, the deficiencies of TCP protocol are becoming more and more distinct. The new TCP implementation, called Receiver Advertisement Based TCP (TCP-Rab) proposed here to eliminate these deficiencies, adopts two basic mechanisms: (1) Bandwidth Estimation and (2) Immediate Recovery. Bandwidth estimation is carried out at the receiver, and the result is sent back to the sender via the acknowledgments. Immediate Recovery guarantees high performance even in lossy link. Rab can distinguish the reason for packet loss, and thus adopt appropriate recovery strategy. For loss by network congestion, it will back off its congestion window, and for loss by link errors, it will recover the congestion window immediately. Simulations indicated that Rab has superiority over other TCP implementations.展开更多
分布式电源(distributed resources,DR)中智能边缘设备数据传输的安全问题为电力系统带来了安全隐患。Modbus TCP(transmission control protocol)协议作为边缘设备采用的通信手段之一,其协议安全性的不足使得系统易遭到网络空间的攻击...分布式电源(distributed resources,DR)中智能边缘设备数据传输的安全问题为电力系统带来了安全隐患。Modbus TCP(transmission control protocol)协议作为边缘设备采用的通信手段之一,其协议安全性的不足使得系统易遭到网络空间的攻击。为保障电力设备数据传输安全,对现有安全手段进行整理,分析现有安全手段在DR应用场景下的不足,提出一种非侵入式Modbus TCP协议安全增强方法。该方法采用云边协同的架构,利用电力控制中心云平台管理访问控制原则,将实际访问控制决策模块部署在边缘设备,并通过细粒度的访问控制组合限制恶意行为。依据Modbus协议参考指南,搭建DR应用场景进行渗透测试,验证该方法能有效防御重放攻击和中间人攻击,可将安全开销控制在百微秒以内,显著优于其他安全手段,满足DR对实时性的需求。展开更多
With the rapid development of the embedded technology, research and implement of the Internet of things will be a new technology revolution, yet the implement of the Internet of things is on the base of the communicat...With the rapid development of the embedded technology, research and implement of the Internet of things will be a new technology revolution, yet the implement of the Internet of things is on the base of the communication between the things. For this reason, realizing the function of communication between singlechip is particularly important. Based on the characteristics of the embedded microcontroller, we analyzed the traditional PC TCP/IP protocol, and appropriately tailored TCP/IP protocol cluster on the basis of the characteristics of embedded singlechip. At last, we realized the reduced TCP/IP protocol cluster suitable for embedded singlechip, on AVR singlechip platform.展开更多
Transmission Control Protocol (TCP) optimization in Mobile Ad hoc NETworks (MANETs) is a challenging issue because of some unique characteristics of MANETs. In this paper,a new end-to-end mechanism based on multiple m...Transmission Control Protocol (TCP) optimization in Mobile Ad hoc NETworks (MANETs) is a challenging issue because of some unique characteristics of MANETs. In this paper,a new end-to-end mechanism based on multiple metrics measurement is proposed to improve TCP performance in MANETs. Multi-metric Measurement based Enhancement of TCP (MME-TCP) designs the metrics and the identification algorithm according to the characteristics of MANETs and the experiment results. Furthermore,these metrics are measured at the sender node to reduce the overhead of control information over networks. Simulation results show that MME-TCP mechanism achieves a significant performance improvement over standard TCP in MANETs.展开更多
The Mimic Defense(MD)is an endogenous security technology with the core technique of Dynamic Heterogeneous Redundancy(DHR)architecture.It can effectively resist unknown vulnerabilities,backdoors,and other security thr...The Mimic Defense(MD)is an endogenous security technology with the core technique of Dynamic Heterogeneous Redundancy(DHR)architecture.It can effectively resist unknown vulnerabilities,backdoors,and other security threats by schedule strategy,negative feedback control,and other mechanisms.To solve the problem that Cyber Mimic Defense devices difficulty of supporting the TCP protocol.This paper proposes a TCP protocol normalization scheme for DHR architecture.Theoretical analysis and experimental results show that this scheme can realize the support of DHR-based network devices to TCP protocol without affecting the security of mimicry defense architecture.展开更多
为提高移动自组网的网络性能和推进Semi-TCP方法的实际应用,提出基于路由协议的Semi-TCP网络层逐跳拥塞控制实现方法。通过在网络层的路由协议中加入拥塞信息广播机制,控制节点对数据包的发送频率,保持链路高速传输数据的同时,降低拥塞...为提高移动自组网的网络性能和推进Semi-TCP方法的实际应用,提出基于路由协议的Semi-TCP网络层逐跳拥塞控制实现方法。通过在网络层的路由协议中加入拥塞信息广播机制,控制节点对数据包的发送频率,保持链路高速传输数据的同时,降低拥塞程度。在EXata仿真平台进行了验证,在设计的动态拓扑实验中,文中方法的吞吐量相比TCP New Reno提高了169.57%,在引入多TCP应用竞争链路后比原Semi-TCP方法提高19.52%,证明了文中方法的有效性。展开更多
文摘With the evolution of network technologies, the deficiencies of TCP protocol are becoming more and more distinct. The new TCP implementation, called Receiver Advertisement Based TCP (TCP-Rab) proposed here to eliminate these deficiencies, adopts two basic mechanisms: (1) Bandwidth Estimation and (2) Immediate Recovery. Bandwidth estimation is carried out at the receiver, and the result is sent back to the sender via the acknowledgments. Immediate Recovery guarantees high performance even in lossy link. Rab can distinguish the reason for packet loss, and thus adopt appropriate recovery strategy. For loss by network congestion, it will back off its congestion window, and for loss by link errors, it will recover the congestion window immediately. Simulations indicated that Rab has superiority over other TCP implementations.
文摘With the rapid development of the embedded technology, research and implement of the Internet of things will be a new technology revolution, yet the implement of the Internet of things is on the base of the communication between the things. For this reason, realizing the function of communication between singlechip is particularly important. Based on the characteristics of the embedded microcontroller, we analyzed the traditional PC TCP/IP protocol, and appropriately tailored TCP/IP protocol cluster on the basis of the characteristics of embedded singlechip. At last, we realized the reduced TCP/IP protocol cluster suitable for embedded singlechip, on AVR singlechip platform.
基金Supported by the National Natural Science Foundation of China (No.60496314)the Chinese 863 National High Technology Program (No.2002AA783043).
文摘Transmission Control Protocol (TCP) optimization in Mobile Ad hoc NETworks (MANETs) is a challenging issue because of some unique characteristics of MANETs. In this paper,a new end-to-end mechanism based on multiple metrics measurement is proposed to improve TCP performance in MANETs. Multi-metric Measurement based Enhancement of TCP (MME-TCP) designs the metrics and the identification algorithm according to the characteristics of MANETs and the experiment results. Furthermore,these metrics are measured at the sender node to reduce the overhead of control information over networks. Simulation results show that MME-TCP mechanism achieves a significant performance improvement over standard TCP in MANETs.
基金supported by the National Key Research and Development Project of China(Grant No.2020YFB1804600)the Major Scientific Project of Zhejiang Lab(2018FD0ZX01).
文摘The Mimic Defense(MD)is an endogenous security technology with the core technique of Dynamic Heterogeneous Redundancy(DHR)architecture.It can effectively resist unknown vulnerabilities,backdoors,and other security threats by schedule strategy,negative feedback control,and other mechanisms.To solve the problem that Cyber Mimic Defense devices difficulty of supporting the TCP protocol.This paper proposes a TCP protocol normalization scheme for DHR architecture.Theoretical analysis and experimental results show that this scheme can realize the support of DHR-based network devices to TCP protocol without affecting the security of mimicry defense architecture.
文摘为提高移动自组网的网络性能和推进Semi-TCP方法的实际应用,提出基于路由协议的Semi-TCP网络层逐跳拥塞控制实现方法。通过在网络层的路由协议中加入拥塞信息广播机制,控制节点对数据包的发送频率,保持链路高速传输数据的同时,降低拥塞程度。在EXata仿真平台进行了验证,在设计的动态拓扑实验中,文中方法的吞吐量相比TCP New Reno提高了169.57%,在引入多TCP应用竞争链路后比原Semi-TCP方法提高19.52%,证明了文中方法的有效性。
