WPathload: A Modified Available Bandwidth Measurement Algorithm
Zeng Bin, Zhang Dafang, Li Wenwei , and Xie Gaogang
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Available bandwidth, as one of the most crucial network resources, directly influences the user perceived performance, and its accurate measurement and estimation is an essential problem in traffic engineering, network monitoring and design of transport protocols. Several tools have, consequently, been proposed to measure end-to-end available bandwidth. Among these tools, Pathload is one of the important methods for measuring available bandwidth. Unfortunately it still has some problems, e.g. the long convergence time and large probe traffic. To solve the problems, WPahtload, a modified available bandwidth measurement algorithm based on delay jitter trend is proposed. In WPahtload, the delay jitter is designed, which can indicate the relationship between the probing rate and the end-to-end available bandwidth. By calculating these parameters, the end system can adjust the transmission rate quickly. Furthermore, the fleet sending rate is used to replace by arrival rate, and then refresh the upper limit of available bandwidth, so that the available bandwidth can be estimated quickly as well as not resulting in large influence on existing traffic. The simulation experiments show that the proposed algorithm WPathload could measure end-to-end path available bandwidth with less overhead and faster convergence rate than that of Pathload. Furthermore, the proposed algorithm tends to be capable of rapidly reflecting changes of bandwidth, thus improving the capability of tracing bandwidth changes.