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Implementation of Dynamic DSCP Adjustment for Effective TCP Transmission on Linux Platform

IETF proposes the Differentiated Service(DiffServ) architecture for next-generation QoS networks. The main features of a DiffServ network are high scalability and compatibility. However, lacking of supporting QoS for individual flows becomes a problem. To remedy this problem, we propose an effective TCP transmission (ETCP) scheme based on the characteristics of TCP.
The goal of this thesis is to make TCP transmission more effective. Because of the network complexity, we need to modify both the Ingress and Egress nodes. At Ingress node, we measure TCP congestion window(cwnd) and Round Trip Time(RTT), while at Egress node we monitor the throughput and embed a feedback ratio into TCP header of the acknowledge packets. When the throughput is below or over the target throughput, we adjust DSCP dynamically. The adjustment depends on both measured TCP congestion window and RTT. Each DSCP value is mapped with a delay time through Delayed-FIFO. Changing the delay time in Ingress node, we are able to control TCP transmission associated with RTT more effectively.
For the purpose of the demonstration, we implement our scheme on Linux platform. We discuss the performance difference between the theoretical and practical results through experiments. Besides, from the implementation, we have shown that our proposed architecture is workable and compatible with today¡¦s network environment.

Identiferoai:union.ndltd.org:NSYSU/oai:NSYSU:etd-0709102-172614
Date09 July 2002
CreatorsCheng, Sheng-Chung
ContributorsCe-Kuen Shieh, Chung-Ming Huang, Wei-Kuang Lai, Tsang-Ling Sheu, Shie-Jue Lee
PublisherNSYSU
Source SetsNSYSU Electronic Thesis and Dissertation Archive
LanguageCholon
Detected LanguageEnglish
Typetext
Formatapplication/pdf
Sourcehttp://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0709102-172614
Rightsunrestricted, Copyright information available at source archive

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