摘要
本文首先对区分服务 (DiffServ)结构中的边缘路由器和核心路由器机制进行了系统的分类研究 ,分析并比较了各种机制 .接着 ,对区分服务结构中TCP的性能问题进行了研究 ,总结了国内外对这一问题的仿真、解析模型分析和实验研究的成果 .找出了关键的问题所在 ,并根据我们的研究成果提出了一些区分服务结构本身的改进建议 .
Firstly, the Diffserv QoS architecture and various edge router marking mechanisms and core router drop mechanisms are discussed in detail. Secondly, this paper examines the several analytic model studies and many simulations on TCP (Transport control protocol) performance in DiffServ Capable IP (Internet protocol) networks. Through analysis, we find that TCP flow using current DiffServ AF PHB can't always achieve assured rate whether by srTCM/trTCM or by TSWTCM. The factors that influence TCP performance are: RTT, target rate, TCP/UDP coexistence and the number of flows in aggregate. What wrong with DiffServ and TCP? We conclude that current DiffServ architecture needs to be enhanced and some per-flow state must be maintained to provide predictive fair service for TCP flows.
出处
《电子学报》
EI
CAS
CSCD
北大核心
2001年第11期1540-1545,1548,共7页
Acta Electronica Sinica
基金
国家自然科学基金项目 (No.69972 0 0 8)和Nokia- BUPT合作项目联合资助
关键词
通信网
因特网
区分服务
TCP性能
Internet
Mathematical models
Network protocols
Queueing theory
Routers
