Analysis of Average Waiting Time and Average Turnaround Time in Web Environment

웹 환경에서의 평균 대기 시간 및 평균 반환 시간의 분석

  • 이용진 (우송대학교 컴퓨터전자정보공학부)
  • Published : 2002.12.01


HTTP (HyperText Transfer Protocol) is a transfer protocol used by the World Wide Web distributed hypermedia system to retrieve the objects. Because HTTP is a connection oriented protocol, it uses TCP (Transmission control Protocol) as a transport layer. But it is known that HTTP interacts with TCP badly. it is discussed about factors affecting the performance or HTTP over TCP, the transaction time obtained by the per-transaction TCP connections for HTTP access and the TCP slow-start overheads, and the transaction time for T-TCP (Transaction TCP) which is one or methods improving the performance or HTTP over TCP. Average waiting time and average turnaround time are important parameters to satisfy QoS (Quality of Service) of end users. Formulas for calculating two parameters are derived. Such formulas can be used for the environment in which each TCP or T-TCP transaction time is same or different. Some experiments and computational experiences indicate that the proposed formulas are well acted, can be applied to the environment which the extension of bandwidth is necessary, and time characteristics of T-TCP are superior to that of TCP. Also, the load distribution method of web server based on the combination of bandwidths is discussed to reduce average waiting time and average turnaround time.


  1. J. Touch, 'TCP Control Block Interdependence,' RFC-2140, ISI, 1997
  2. 한국전자통신연구소, '전자거래에서 디렉토리를 위한 에이전트 연구', pp.56-108, 1997
  3. R. W. Stevens, CP/IP Illustrated : TCP for Transactions, HTTP, NNTP, and the UNIX Domain Protocols. Reading : Addison-Wesley, Vol.3, 1996
  4. R. W. Stevens, UNIX Network Programming : Appendix 4(Timer Routine), Prentice-Hall, 1991
  5. J. Touch, J. Heidemann and K. Obraczka, 'Analysis of HTTP Performance,' USC/Information Sciences Institute, 1996
  6. V. Padmanabhan and J. Mogul, 'Improving HTTP Latency,' Proc. of the Second International WWW Conference, 1994
  7. E. Rescorla and A. Schiffman, 'The secure Hypertext Transfer Protocol,',' Internet Draft., 1996
  8. S. E. Spero, 'Next Generation Hypertext Transport Protocol,' Internet Draft, 1995
  9. J. Mogul, 'The Case for Persistent-Connection HTTP,' ACM Sigcomm '95, pp.299-313, 1995
  10. J. Mogul and S. Deering, 'Path MTU Discovery,' RFC-1191, DECWRL, Stanford University, 1990
  11. J. Postel, 'Transmission Control Protocol,' RFC-793/STD-007, September, 1981
  12. V. Jacobson, 'Congestion Avoidance and Control,' ACM Sigcomm '88, 1988
  13. V. Jacobson and M.Karels, 'Congestion Avoidance and Control,' ACM CCR, Vol.18, No.4, pp.314-329, 1990
  14. J. Heidemann, K. Obraczka and J. Touch, 'Modeling the Performance of HTTP Over Several Transport Protocols,' IEEE/ACM Transactions on Networking, Vol.5, No.5, pp.616-630, 1997
  15. J. Heidemann, 'Performance Interactions Between P-HTTP and TCP Implementations,' ACM Computer Communications Review, pp.65-73, 1997
  16. R. Braden, 'T/TCP-TCP Extensions for Transactions : Functional Specification,' RFC-1644, 1994
  17. T. Faber, J. Touch and W. Yue, 'Avoiding the TCP TIME_WAIT state at Busy Servers,' ISI, 1997
  18. R. Fielding, H. Frystyk and T. Berners Lee, 'Hypertext Transport Protocol-HTTP/1.1,' Internet Draft, 1996
  19. T. Berners Lee, R. Fielding and H. Frystyk, 'Hypertext Transfer Protocol-HTTP/1.0,' RFC-1945, 1995
  20. R. Braden, 'Extending TCP for Transactions-Concepts,' RFC-1379, 1992