(A) study on congestion control algorithm using edge router in differentiated service

Abstract

When too many users send data too high rate at once, the queue of router will overflow and data will be dropped. Such a situation is called congestion and an algorithm to solve congestion is called a congestion control. Current internet uses Tahoe and Reno of TCP(Transmission Control Protocol) to solve congestion problem. However, since they cannot get network information directly from network, they have global synchronization, bias to longer rtt(round trip time) and unfairness. To solve those problems, we introduce DS (Differentiated Service) network and think that edge router of DS network can send network information to sender. So, we can do network-assisted congestion control, and problems of Tahoe/Reno can be solved. In this thesis, we propose a congestion control algorithm with assistant of edge router. We mathematically analyze our algorithm and verify the result by simulation.