摘要： CDN是一种基于的网络体系结构,能够更加快速有效地传送内容。它采用缓存、复制、负载均衡和客CDNWebWeb户请求重定向等技术,基于构筑一个地理上分布的内容分送网络,将信息资源推向网络边缘,使得用户可以从Internet 最近最好的服务器快速访问到所需的内容,从而大大提高终端用户的访问速度。是比较新的技术系统,本身仍然""CDN处于高速发展的阶段,需要解决和完善一些关键技术问题;更为重要的是,目前还缺乏一个标准来评测网络和CDNCDN产品的性能。提供了一个良好的测量性能的平台,从而使得可以从网络内部,从、和终端用户的角CERNETCDNISPICP度出发考查技术,从而为的布置和发展提供有用的数据。文章简要分析了技术提高网络性能的原因;建立CDNCDNCDN若干评测性能的参数,给出参数的定义,以及这些参数对评测性能的意义;给出在上对进行测量CDNCDNCERNETCDN的若干结果;并对及其性能的测量给出初步的评述。

关键词: 内容分送网络, CERNET, 性能, 参数

Abstract: CDN (content distributed/delivery network) is a network architecture based on Web. It can deliver Web contents more quickly and more efficiently. By making use of caching, duplication, load balancing and user request redirection, CDN constructs a large-scale content distributed network upon Internet. CDN pushes information resources to network edges to provideend users with the best and most available servers to access various contents. CDN is quite a new system of techniques and developing rapidly. It must solve and improve some key problems. What's more important is that we lack a standard to evaluate the performance of CDN and its relative products. CERNET provides us a favorable platform to measure CDN performance, for we can inspect those CDN techniques from inside the network and from the point of view of ISP, ICP and end users, so as to get useful information for deploying and developing a CDN. A brief view of reasons for CDN's enhancing network performance is firstintroduced in this paper, followed by several metrics, their definitions and significance to evaluate a CDN's performance. Some measurement results are covered to evaluate a CDN's application on CERNET as the central part. In addition, some fundamental comments on CDN and its measurement are given.

中图分类号: 

• TP393.02