拒绝服务攻击的探讨

拒绝服务攻击对网络构成了巨大的安全威胁,由于网络协议本身是不安全的,所以处理分布式拒绝服务攻击是困难的。     

拒绝服务攻击的研究与探讨

拒绝服务攻击是黑客经常采用并且极为有效的网站攻击手段，它利用了用户必须采用的TCP／IP协议的漏洞，较难防范。本文介绍了拒绝服务攻击的原理和常用方法，分析了分布式拒绝服务攻击的工作原理，并讨论了防范攻击的几种主要方法。     

分布式拒绝服务攻击手段与应对策略

分布式拒绝服务攻击是一种利用了TCPAP协议缺点的网络攻击方法.论述了分布式攻击的手段,分析了其特点,和针对它的检测方法及应对策略.     

分布式拒绝服务攻击防御性能评估方法研究

分布式拒绝服务攻击（Distribution Denial of service,DDos）是对互联网服务的可靠性与稳定性的严重威胁．为了有效、客观的评估各种防御DDoS攻击的技术,本文经过对传统的DDoS防御性能评估方法分析之后,提出了一种基于应用的DDoS防御性能评估方法,并采用实验模型获得测试数据．通过测试数据说明,该方法是一种有针对性的、综合的并且通用的评估方法．     

分布式拒绝服务攻击手段与应对策略

分布式拒绝服务攻击是一种利用了TCPAP协议缺点的网络攻击方法。论述了分布式攻击的手段，分析了其特点，和针对它的检测方法及应对策略。     

防火墙的工作原理和防止拒绝服务攻击的方式

防火墙指的是隔离本地网络与外界网络之间的一道防御系统。在互联网上,防火墙是一种非常有效的网络安全模型,通过它可以隔离风险区域与安全区域的连接,同时不会妨碍人们对风险区域的访问。     

拒绝服务攻击防御方案思考

随着网络的发展,拒绝服务攻击成为了网络安全的头号敌人。它具有的高强度特征和高隐蔽性导致其破坏力很大。对于拒绝服务攻击的防御,本文从预防、检测和响应三个阶段,针对各个阶段的特性,引入了具有实际可行性的思路。对各种方案,总结了其优缺点,便于进一步的改善,早日形成一个完善的防御体系。     

基于DDOS攻击机理的分析与防范

分布式拒绝服务（DDOS）是目前威胁网络安全并严重影响网站服务的一种新的攻击方法。它比拒绝服务（DOS）更加隐蔽，危害性更大。章详细分析了这种攻击方法的机理和特征，并就此提出了相应的防范措施。     

一种基于聚类与关联规则算法的DDoS攻击检测模型

分布式拒绝服务（Distribute Denial of Service）攻击是当前主要的网络安全威胁之一．本文分析了DDoS攻击的本质特征,提出了一种基于数据挖掘算法的DDoS攻击检测模型．该模型使用聚类算法与关联规则对网络流量与网络数据包连接状态分别建立特征模型,并确定DDoS攻击的检测阈值．实验表明,该检测模型能够实时有效的检测DDoS攻击．     

拒绝服务攻击原理与防御策略

介绍了拒绝服务攻击实施的原理，以及相关协议的漏洞和拒绝服务攻击的最新进展，并说明了如何结合防火墙和入侵检测系统等手段来防范其攻击。     

两种无线局域网安全标准WAPI与 IEEE802.11i的比较

本文从两个标准的技术实质与工作原理两方面来加以分析和比较，并在文末预测了它们的前景。     

DDoS/DRDoS攻击的研究与设计

DDoS攻击（包括DRDoS攻击）给网络安全带来了巨大的危害。为了阻止这类攻击,本文从分析当前DoS/DDoS攻击的原理入手,对DDoS/DRDoS攻击进行合理分类,即分为协议漏洞攻击、软件漏洞攻击和蛮力攻击三种。具体介绍了DRDoS攻击的程序实现,同时设计了可以进行这类攻击的攻击平台。     

IEEE 802.11协议直扩技术的实现

802.11标准直扩技术主要是对网络的物理层(PH)和媒质访问控制层(MAC)进行了规定,其中对MAC层的规定是重点.同一物理层上可以互操作,逻辑链路控制层(LLC)是一致的,即MAC层以下对网络应用是透明的.这样就使得无线网的"(同网段内)多点接入"和"多网段互连",易于质优价廉地实现.     

Performance Improvement of Distributed Coordination Function in IEEE 802.11 Wireless LAN

This paper proposes a modification to distributed coordination function (DCF) to improve the channel utilization in IEEE 802.11 wireless local area networks (WLANs). In the modified DCF, when a station has contended for the channel, it may transmit multiple data frames continuously to the same destination, which is called transmission burst(TB). When the maximum number of data packets transmitted continuously in a TB is set to be 2, the performance is expected to be the best. The theoretical analysis and simulation results show that compared with the standard DCF, the modified DCF can increase the throughput and decrease the delay of the WLAN, and the modification does not introduce any additional control overhead.     

Performance analysis of IEEE 802.11 DCF networks

This paper presents an analytical saturation throughput model of IEEE 802.11DCF （distributed coordination function） with basic access in ad hoc mode. The model takes into account freezing of the backofftimer when a station senses busy channel. It is shown that taking into account this feature of DCF is important in modeling saturation throughput by yielding more accurate and realistic results than models known from literature. The proposed analytical model also takes into account the effect of transmission errors. All essential features of the proposed analytical approach are illustrated with numerical results. The presen- tation of the model is proceeded by an overview of approaches to IEEE 802.11 network performance evaluation presented in the literature.     

IEEE 802.11网络中服务质量支持机制的研究

如何保证实时业务(如VoIP、AoD和VoD等多媒体业务)的服务质量是目前无线通信领域的一个重要课题。本文概述了现有的IEEE 802．11中服务质量支持机制,包括基于 MAC层的区分服务机制、基于MAC以上层的接纳控制和带宽预留机制等,对实现复杂性、兼容性和资源利用率等进行了简要分析。     

无线局域网IEEE802.11标准浅析

介绍无线局域网的IEEE802.11标准的常用标准,及其为满足不同要求指定的特殊标准,分析了各具体标准的基本特性、特征,以及它们的适用范围和发展前景,对读者了解WLAN的IEEE802.11系列标准的有关知识有一定的帮助.     

Finite time-horizon Markov model for IEEE 802.11e

We model wireless local area network channel utilization over a finite interval through a finite time-horizon Markov （FTHM） model. By accurately capturing time-varying utilization, the FTHM model allows for generally distributed transmission-opportunity （TXOP） duration, which most existing models do not account for. An absorbing state is introduced to limit the lifetime of the counting process, resulting in a non-ergodic Markov chain that is solved via transient analysis. The model predictions for time-varying utilization are validated by simulation with errors of no more than 0.1% after eight beacon intervals. Moreover, we show that the FTHM model prediction error is below 4% for Poisson distributed and uniformly distributed TXOP durations.     

Performance Improvement of DCF Supporting Multi-Rate in IEEE 802.11b Wireless LAN

Inrecent years ,IEEE802.11 wirelesslocal area net-work (WLAN) has emerged as a prevailing technology forthe (indoor) broadband wireless access to internet for themobile/portable devices . In IEEE 802.11 standards ,802.11b has become the most widely used v…     

Performance analysis of IEEE 802.11e EDCA in wireless LANs

INTRODUCTION IEEE 802.11e is designed to support multimedia applications. The main and mandatory scheme of IEEE 802.11e standard is enhanced distributed channel access (EDCA), which adopts service dif-ferentiation in configuration. The performance analysis of EDCA has been extensively studied by analytical or numerical means in recent years (Kong et al., 2004; Xiao, 2005; Zhu and Chlamtac, 2005; Hui and Devetsikiotis, 2005; Zhang et al., 2006). With the help of these works, perf…