Research On The Available Bandwidth Measurement Factors And Method Improvement

As Internet growing rapidly, more and more network applications need to hold the network information to monitor network utilization and performance. Network bandwidth, especialy available bandwidth is a very important factor. Recently, many available bandwidth arithmetics are interesting in the basic network transmit characters, but these arithmetics are not analyze and explain the effects of cross traffic on available bandwidth estimation, the real measure reasults are not answere our needs.Aim at the question, in this thesis, we focus mainly on the available measurement process and measurement methods, try to construct a effective framework in the network bandwidth measurement, comprehend the basic rules in the network applications, attain accurate available bandwidth information, establishes the base of network available bandwidth measurement, and the main works are as follow:1. Face the problem of some bandwidth notions are not clear, the thesis specific defines link bandwidth, available bandwidth and throughput, these notions helps bandwidth measurement.2. Proposes a classified method based on intrinsic and external factors. This method is concerned with the factors in the process of measurement, primary includs processing packets sizes, packets dispersion, cross traffic and network delay. The method helps to research a new bandwidth arithmetic.3. Proposes a new available bandwidth method which based on queuing and accumulated delay. Firstly, builds a relation among the input probing gap, output probing gap and queuing delay; Secondly, analyze the relation between the rate of packet pair and available bandwidth; Finally, adjusts the probing rate through binary search, obtained the available bandwidth.4. The thesis use simulation tool NS-2 and network real experiment simulated and implemented the proposed arithmetic. The simulated envionments includes one-hop and multi-hop network, compares measurement results and consume time among three kinds of tools, the experiment results show that the proposed method has a better effect.From the above work, the influencing factors classified method and the queuing-based available bandwidth measurement which the paper have proposed provide useful complementation and expansion for network bandwidth measurement, also, the application of this technique provides theory and practise value.