用RAM进行时延分布统计  

Statistics of Delay Distribution in RAM

作　　者：吴义宝[1] 陆增援[1] 安琪[1] 

机构地区：[1]中国科学技术大学近代物理系,合肥230027

出　　处：《电子测量与仪器学报》2004年第1期78-82,共5页Journal of Electronic Measurement and Instrumentation

摘　　要：本文介绍了一种对通讯中的时延参数的分布进行统计的RAM实现方法。该方法使用发送和接收的时间戳来计算时延的大小 ;根据设定的参数 ,用指定数目的时延值计算预估平均值 ;根据设定的分辨率参数 ,对时延值与预估平均值的差值进行直方图统计。在该方法中 ,处理了时延的差值计算以及直方图统计中可能出现的上、下越界问题 ,并使用软件与硬件配合进行计数 ,可长时间工作。该方法在硬件中实现 ,可明显减少软件与硬件的通讯 ,减轻软件处理的负担。该方法已经成功应用在宽带网络测试仪中 。In this article, a solution of statistics of delay distribution in RAM is introduced. The timestamp of transmission and receipt is used to calculate the delay. The predicted average value is calculated based on specified number of delay, and the difference of delay and the predicted average value is calculated, then processed and used to construct the histogram. The overflow and underflow in calculation of difference and processing of difference is considered, and the cooperation of software and hardware in counting is considered to make it work for a long time. It is implemented in hardware, which can reduce the traffic between software and hardware effectively, and reduce the burden of software. It was used successfully in Broad-band Test System, and it also can be used in other statistics or measurement of distribution.

关 键 词：时延 服务质量 分布 统计 RAM 通信 计算机网络 

分 类 号：TP393[自动化与计算机技术—计算机应用技术]