Estimation of network characteristics and its use in improving performanceof network applications

Network applications such as FTP, WWW, Mirroring etc. are presently operate d with little or no know-ledge about the characteristics of the underlying network. These applications could operate more efficiently if the character istics of the network are known and/or are made available to the concerned application. But network characteristics are hard to come by. The IP Perfor mance Metrics working group (IETF-IPPM-WG) [6] is working on developing a s et of metrics that will characterize Internet data delivery services (netwo rks). Some tools are being developed for measurements of these metrics [5]. These generally involve active measurements or require modifications in ap plications[16]. Both techniques have their drawbacks. In this work, we show a new and more practical approach of estimating network characteristics. T his involves gathering and analyzing the network's experience. The experien ce is in the form of traffic statistics, information distilled from managem ent related activities and ubiquitously available logs (squid access logs, mail logs, ftp logs etc.) of network applications. An analysis of this expe rience provides an estimate of the characteristics of the underlying networ k. To evaluate the concept we have developed and experimented with a system wherein the network characteristics are generated by analyzing the logs an d traffic statistics. The network characteristics are made available to net work clients and administrators by Network Performance Metric (NPM) servers . These servers are accessed using standard network management protocols. R esults of the evaluation are presented and a framework for efficient operat ion of network operations, using the network characteristics is outlined.