Rmon Network Buffer Management Studies

Quality of Service(QoS)of Fieldbus traffic in Internet/Intranet is one of the most important technologies to realize remote control for Fieldbus. In TCP/IP networks, congestion control mechanism of Internet and quality of service are two interrelated research subjects. The paper researches on QoS of Fieldbus traffic from the point of view of buffer management.Traffic modelling is the base of buffer management. The paper demonstrates that the traffic of Foundation Fieldbus (FF) is statistically self-similar, that none of the commonly used traffic models is able to capture this fractal behaviour, that such behaviour has serious implications for the design, control, and analysis of Infranet and Intranet, and that aggregating streams of such traffic typically intensifies the self-similarity instead of smoothing it. The paper analyzes the reason why self-similar process is built on the superposition of AR1 processes and the superposition of other self-similar processes. After concluding that the traffic has self-similarity in Foundation Fieldbus, we use Weibullian model to construct the overflow probability of H1 traffic and estimate its parameters.Queuing management is not only kernel technology of QoS, but also important artifice of congestion avoidance of network. This algorithm that divides queuing management into two mutual independent modules and brings forward SCQS structure based on CQS structure solves the processing of an outburst of data flow efficiently. Furthermore, the algorithm is realized easily so it is fit for QoS queuing management of real time networks.In order to solve the transportation of Fieldbus traffic in Internet or large scale Intranet, we propose a new protocol marking strategy. First, the strategy uses APP packets of RTCP to accomplish real-time transportation of Fieldbus traffic. Secondly, because of connectionless service of UDP, the strategy makes use of program control of application layer to realize acknowledgement of packets and fast retransmission. Finally, the strategy neglects the influence on misbehaving flow by admission control and buffer management.