An Improved Random Early Detection (RED) Algorithm for Congestion Control

• Main Authors: Wei-Chung Lin, 林偉正
• Other Authors: Wen-Shen E.chen
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/16896950377494718155

碩士 === 國立中興大學 === 資訊科學系所 === 95 === Many proposals have been adopted in controlling the congestions in the routers, including Random Early Detection (RED) and Drop-tail, and have shown to improve the loss rate, throughput, fairness, etc. of the network. Although RED algorithm is designed for TCP for a active queue management, we found that when comes to dropping the packets, it treats packets equally, ignoring the effect of the the size of the packets. This results in higher loss rate of packets and lower throughput for smaller packets. In this thesis, we propose to improve the original RED algorithm by differentiating packet sizes and devise RED_average algorithm and further improved PS_average algorithm. We then use ns-2 to simulate the performance of the aforementioned three algorithm.based on three MTU sizes. The results showed that if we take the factor of the packet size into consideration, the RED_average algorithm has a better loss rate and throughput. The PS_average, which takes the average packet size into consideration to adjust the intended loss rate for smaller packates, has a even further improved performance. We have shown that by the above two new algorithms, a better balance for the loss rate for all packets can be achieved, and thus improved utilization of the network resources.