Using Sequence Number Compensation to Design DCCP Partial Reliability Extension
Datagram Congestion Control Protocol (DCCP), possessing congestion control and unreliable transmission, specially suits real-time multimedia applications. Nevertheless, losses of key packets will cause a substantial decline on quality of services (QoS) in some applications. This paper proposes a DCCP partial reliability extension (PRDCCP) that can retransmit lost packets as needed. Since DCCP uses an incremental sequence number, the retransmitted packets cannot utilize their original sequence number. To solve this problem, PR-DCCP adopts sequence number compensation, which appends an offset to the retransmitted packet; thus the receiver can use the sequence number of this retransmitted packet and the attached offset so as to re-obtain the original sequence number. The simulation uses two performance metrics: Decodable Frame Ratio (DFR) representing QoS, and Useless Data Received Ratio (UDRR) representing the bandwidth waste. These are used to evaluate different transport protocols, namely, PR-DCCP, DCCP, SCTP, TCP, and UDP. Simulation results show that PR-DCCP has the better DFR and UDRR than other transport protocols in almost all cases. For various movies, a DFR of PR-DCCP is 1.2％ -12.4％ higher than that of DCCP; while UDRR is lower by 73.2％ -85.1％. Furthermore, the reliability policies to determine which packets require reliability are investigated.
DCCP Multimedia application Partial reliability Retransmission
Yuan-Cheng Lai Yi-Hsuan Yeh Ching-Neng Lai Jian-Wei Lin
Department of Information Management National Taiwan University of Science and Technology Taipei, Ta Department of Information Management Oriental Institute of Technology Taipei, Taiwan Department of Information Technology Hsing Wu College Taipei, Taiwan Department of International Business Management Ching Yun University Taoyuan, Taiwan
国际会议
上海
英文
50-55
2010-06-22（万方平台首次上网日期，不代表论文的发表时间）