Design and Analsis of a high speed switching system with two priority

두개의 우선 순위를 가지는 고속 스윗칭 시스템의 설계 및 성능 분석

  • Published : 2001.12.01

Abstract

In the recent priority system, high-priority packet will be served first and low-priority packet will be served when there isn\`t any high-priority packet in the system. By the way, even high-priority packet can be blocked by HOL (Head of Line) contention in the input queueing System. Therefore, the whole switching performance can be improved by serving low-priority packet even though high-priority packet is blocked. In this paper, we study the performance of preemptive priority in an input queueing switch for high speed switch system. The analysis of this switching system is taken into account of the influence of priority scheduling and the window scheme for head-of-line contention. We derive queue length distribution, delay and maximum throughput for the switching system based on these control schemes. Because of the service dependencies between inputs, an exact analysis of this switching system is intractable. Consequently, we provide an approximate analysis based on some independence assumption and the flow conservation rule. We use an equivalent queueing system to estimate the service capability seen by each input. In case of the preemptive priority policy without considering a window scheme, we extend the approximation technique used by Chen and Guerin [1] to obtain more accurate results. Moreover, we also propose newly a window scheme that is appropriate for the preemptive priority switching system in view of implementation and operation. It can improve the total system throughput and delay performance of low priority packets. We also analyze this window scheme using an equivalent queueing system and compare the performance results with that without the window scheme. Numerical results are compared with simulations.

기존 우선 순위 시스템에서는 우선 순위가 높은 패킷이 시스템에서 우선적으로 서비스를 받고 우선 순위가 낮은 패킷은 우선 순위가 높은 패킷이 없을 경우에만 서비스 받도록 되어있다. 그러나 입력 큐잉 시스템에서는 HOL(Head of Line)경쟁에 의해서 우선 순위가 높은 패킷이라도 차단 될 확률이 높다. 따라서 우선 순위가 높은 패킷이 차단됐을 경우라도 우선 순위가 낮은 패킷을 서비스 해 줌으로써 전체적으로 스윗칭 성능을 향상 시킬 수 있다. 본 논문은 고속 스위칭 시스템에서의 우선순위 기반 방식의 성능 분석을 하였다. 스윗칭 시스템 분석은 HOL(Head of line)경쟁 현상에 대한 우선순위 스케쥴링이 미치는 영향을 고려 하였다. 또한 이러한 제어방식을 기반으로 시스템의 최대 처리율, 큐잉 분포현상을 도출 하였다. 입력단 간에 서비스 의존도 때문에 스윗칭 시스템의 정확한 분석은 어려우나 상호 의존성을 갖는다는 가정과 흐름제어 규정을 두어 분석을 하였다. 각각의 입력단에서 보여주는 서비스 향상을 평가 하기위해 큐잉 시스템을 이용 하였다. 윈도우 방식을 고려하지 않고 우선순위 방식에서 정확한 결과를 구하기 위하여 Chen과Guerin[1]가 사용한 방식을 확장 하였다. 더욱이 시스템 구현과 운영 관점에서 우선순위 스윗칭 시스템에 적용하기 위하여 새로운 윈도우 제어방식을 제안한다. 그러므로 우선순위가 낮은 패킷은 지연시간과 처리율을 향상 시킬 수 있다. 성능 향상을 위해 결과치를 비교하여 등가 큐잉시스템을 사용하여 윈도우 방식을 분석 하였다.

Keywords

References

  1. J. S.-C. Chen and R. Guerin, 'Performance study of an input queueing packet switch with two priority classes,' IEEE Trans. Commun, Vol.39, pp.117-126, Jan. 1991 https://doi.org/10.1109/26.68282
  2. H. Ahmadi and W. E. Denzel, 'A survey of modem high-performance switching techniques,' IEEE J. on Selected Areas Commun., Vol.SAC-7, No.7, Sept. 1989 https://doi.org/10.1109/49.44557
  3. Y. S. Hui, switching and Traffic Theorg for lntefrated BroadBand Network, Kluwer Academic publisher, Boston, 1990
  4. J. Y. Hui and E. Arthurs, 'A broadband packet switch for integrated transport,' IEEE J. Select. Areas Commun., Vol.SAC-5, pp.1264-1273, Oct. 1987
  5. I. Iliadis, 'Performance of a packet switch with input and output queueing under unbalanced traffic,' in Proc. INFOCOM '.92, pp.743-752. June, 1992 https://doi.org/10.1109/INFCOM.1992.263501
  6. J. N. Giacopelli,W. D. Sincoskie andW. Littlewood, 'Sunshine : a high performance self routing broadband packet switch architecture,' in Proc. XIII International Switcing Symposium, '90, Stockolm Sweden, May, 1990
  7. H. Suzuki et al., 'Output-buffer switch architecture for asynchronous transfer mode,' in Proc ICC '89, pp.99-103 June, 1989 https://doi.org/10.1109/ICC.1989.49676
  8. M. Yamamoto, H. Tode, H. Okada and Y. Tezuka, 'A control-ahead ATM switch architecture and its performance,' IEEE Jon Selected Areas Commun., Vol.SAC-9, No.9, Dec. 1991 https://doi.org/10.1109/49.108690
  9. M. G. Hluchyj and M. J. Karol, 'Queueing in high-performance packet switching,' IEEE J. Select. Areas Commun., Vol.SAC-6, pp.1587-1597, Dec. 1988 https://doi.org/10.1109/49.12886
  10. M. Karol and M. G. Hluchyj, 'Using a packet switch for circuit-switched traffic : A queueing system with periodic input traffic,' IEEE Trans. Commun., Vol.37, pp.623-625, June, 1989 https://doi.org/10.1109/26.31146
  11. M. Karol, M. G. Hluchyj, and S. P. Morgan, 'Input versus output queueing on a space-division packet switch,' IEEE Trans, Commun., Vol.35, pp.1347-1356, Dec. 1987 https://doi.org/10.1109/TCOM.1987.1096719
  12. S. Li and M. J. Lee, 'A study of traffic imbalances in a fast packet switch,' in Proc. INFOCOM '8.9,1989, pp.538-547 https://doi.org/10.1109/INFCOM.1989.101498
  13. Y. Lim and J. Kobza, 'Analaysis of a delay-dependent priority discipline in a multi-class traffic packet switching node,' IEEE Trans. Commun., Vol.38, pp.659-665. May, 1990 https://doi.org/10.1109/26.54979
  14. A. Iyengar and M. E. Zarki, 'Switching prioritized packets,' in Proc. GLOBE COM '89, pp.1181-1186, 1989 https://doi.org/10.1109/GLOCOM.1989.64141
  15. A. Y-M. Lim and J. A. Silverster, 'Priority queuing strategies and buffer allocation protocols for traffic control at an ATM integrated broadband switching system,' IEEE J. on Selected Areas Commun., Vol.SAC 9, pp.1524-1536. Dec. 1991 https://doi.org/10.1109/49.108688
  16. G. Kesides and N. Mckeown, 'output buffered ATM packet switching for Integrated services communication Networks,' IEEE ICC '97, 1997 https://doi.org/10.1109/ICC.1997.595074
  17. Y. K. Park and G. Lee, : NN based ATM Cell Scheduling with Queue length_Based priority schene. IEEE JSAC. Vol.15, No.2, pp.261-270, Feb. 1997 https://doi.org/10.1109/49.552075
  18. Adisak Mekkittikul, and Nick McKeown, 'A practical scheduling Algorithm to Achieve 100% Through put in input-Queued switches,' IEEE infocom '98, 1998 https://doi.org/10.1109/INFCOM.1998.665102
  19. A. K. Gupta and N. D Georgans, 'Priority performance of ATM packet switches,' in Proc. IINFOCOM '92, pp.772-733, June, 1992 https://doi.org/10.1109/INFCOM.1992.263498
  20. K. W. Sarkies, 'The bypass queue in fast packet switching,' IEEE Trans. Commun., Vol.39, pp.766-774, May, 1991 https://doi.org/10.1109/26.87139
  21. A. Y. M. Lim and J. A. Silverster, 'Priority queueing strategies and buffer allocation protocols for traffic control at an ATM intefrated broadband switching system,' .lEE J. on Selected Areas Commum., Vol.SAC-9, pp.1524-1536, Dec. 1991 https://doi.org/10.1109/49.108688