一种改进的ARED主动队列管理算法  

An Improved ARED Active Queue Management Algorithm

作　　者：张卓[1] 周井泉[1] 张萌[1] 

机构地区：[1]南京邮电大学电子科学与工程学院,江苏南京210003

出　　处：《计算机技术与发展》2015年第10期59-62,66,共5页Computer Technology and Development

基　　金：江苏省普通高校研究生科研创新基金(CXLX12_0471)

摘　　要：RED算法是一种非常有效地避免网络拥塞的主动队列管理算法。ARED算法也是重要的主动队列管理算法之一,RED的改进算法,通过检测平均队列长度来判定网络拥塞程度,调节最大丢包概率来稳定队列长度,存在网络的滞后性和参数设置敏感问题。为了使该算法平均队列长度更加稳定并且减小丢包率,文中提出H-ARED算法,采用分段函数对ARED算法的丢包概率函数进行优化,在平均队列长度最大阈值maxth之后增加一个参数Hth,当平均队列长度大于maxth时数据包不会被全部丢弃。该算法充分利用路由器缓冲区的大小,控制队列长度,使之能够更好地控制网络拥塞,降低网络数据分组丢包概率。通过NS2网络仿真工具进行仿真,结果表明:H-ARED算法改善了平均队列长度的稳定性,降低了数据丢包率,对于复杂的网络环境适应性较强。RED is an active queue management algorithm that avoids network congestion effectively. ARED algorithm is also one of the important active queue management algorithms, an improved RED algorithm, which can determine the degree of network congestion through detecting the average queue length, and regulate the maximum drop probability to achieve the effect of a stable queue length. However, the network is lag and cannot adapt to the network busty traffic well. In order to make average queue length more stable and re- duce packet loss rate,H-APED algorithm is proposed in this paper, which uses piecewise function to optimize the packet loss probability function of the ARED algorithm and adds a parameter Hth after the maximum threshold maxth of the average queue length. The data will be not all dropped when the average queue length is greater than the maximum threshold maxth. Within the range of the router buffer, it takes full advantage of the router buffer, so that it can better control network congestion, reducing network packet loss probability. Through simulation using NS2 network simulation tool, the results show that H-ARED algorithm improves the stability of the average queue length, reduces packet loss rate and has a stronger robustness in the complex network environment.

关 键 词：主动队列管理 ARED算法 概率函数 平均队列长度 

分 类 号：TP306.1[自动化与计算机技术—计算机系统结构]