区分服务环境下TCP拥塞控制机制研究

A New TCP Congestion Control Mechanism for Differentiated Services

区分服务能为不同服务需求的用户提供相应的服务质量,TCP流量在Internet中占有重要的地位,TCP基于窗口的拥塞控制算法限制了具有大RTT连接公平获得带宽,进而限制了TCP对区分服务的支持,因此研究TCP在区分服务体系结构下的拥塞控制机制具有重要的意义。基于提出的一种支持区分服务的主动队列管理机制EBLUE,结合改进的TCP拥塞控制机制,研究了TCP在区分服务环境下对确保服务的支持,即使在经历拥塞时,TCP连接也能公平地获得其流量规格中说明的带宽。最后,在ns 下的仿真实验结果验证本文机制的有效性和公平性。

Differentiated services can provide different QoS for different user demands. TCP plays an important role in the Internet, but TCP抯 window-based congestion control algorithm impairs long RTT connections to achieve fair bandwidth share and support differentiated services, so researches on TCP congestion control for differentiated services is a meaningful job. This paper presents an active queue mechanism, EBLUE, and improves TCP congestion control algorithm. Then by combining two technologies, we investigate how TCP supports assured service and achieves fair bandwidth share among connections. The simulation results testify that our mechanism is feasible and fair.