Reducing the Impact of Continuous Media on TCP Flows by a TCP-Friendly Shaper

• Main Authors: Yi-Chung Liu, 柳奕仲
• Other Authors: Ying-Dar Lin
• Format: Others
• Language: en_US
• Published: 2002
• Online Access: http://ndltd.ncl.edu.tw/handle/81211581676402449816

碩士 === 國立交通大學 === 資訊科學系 === 90 === In recent years, streaming traffic has been employed in the Internet world with a rapid increase, most of which is preferably carried by the UDP transport protocol because of certain continuous media concerns. In addition, the RTP and RTCP, embedded with appropriate information, are generally employed to enhance original UDP with continuous media applications when multimedia data are transmitted. However, these protocols do not address any mechanism for congestion control and thus under such a non-congestion controlled situation, coexisting TCP and UDP traffic can lead to congestion collapse, which degrades the performance and utilization of the network. In this work, we propose a mechanism called Adaptive Shaper (AS) inclusive of the rate-smoothing component and the TCP-Friendly congestion control component. It is expected to reduce the harm for TCP flows by gathering the network traffic loading information and adjusting the sending rate of the streaming flow. As the bandwidth resource is sufficient, the rate-smoothing component takes advantage of the variations in queue length to dynamically estimate the arrival rate of the streaming traffic which reduces the fluctuation of the rate effectively. While, as the network is congested, the TCP-Friendly congestion control component forces the streaming flow to respond to the congestion and immediately prevent TCP flows from starvation. Finally, the simulation results present that the adaptive shaper increases the efficiency of the network form 92.5% to 99.5% and reduces the impacts of continuous media on TCP flows.