Vasilios A. Siris July 1997 These are some typical values of s,t (computed using the supinf formula [CW96]) for C=34, 155, and 622 Mbps links and a range of buffer sizes. The buffer overflow probability is approx. 10^-7. The source is an MPEG-1 sequence containing a segment of the Star Wars movie [Ros95]. In each frame, the cells are assumed to be evenly distributed. No other smoothing is assumed. The sequence contains 40,000 epochs of 40 msec each (total duration approx 30 minutes). The original sequence was segmented into 48 byte payload cells (for simplicity I have not considered other overhead, e.g. AAL). Other MPEG files, for the same values of C,B, and CLP, give approximately the same product s*t. See [CSS98] for details regarding experiments with real traffic. Trace Mean (Mbps) Peak(Mbps) Star Wars 0.29 3.46 The other variables in the table are the following: B: buffer size in cells D: buffer size in msec. This is computed using D=B/R, where R is the cell transfer rate. R=34,149,600 Mbps for C=34,155,622 Mbps s: in kb^-1 t: in msec Link: C=34 Mbps D(msec) B(cells)s(kb^-1) t(msec) -------------------------------------- 1 80 3.27 E-02 40 2 160 3.23 E-02 40 4 320 3.16 E-02 40 6 481 3.06 E-02 40 8 641 3.01 E-02 40 10 801 2.98 E-02 40 15 1202 2.82 E-02 40 20 1603 1.42 E-02 160 25 2004 2.08 E-03 1560 30 2405 1.99 E-03 1560 40 3207 1.57 E-03 2080 50 4009 1.13 E-03 2880 Link: C=155 Mbps (ATM cell transfer rate approx. 149 Mbps) D(msec) B(cells)s(kb^-1) t(msec) -------------------------------------- 1 351 1.56 E-02 40 2 702 1.55 E-02 40 4 1405 1.52 E-02 40 6 2108 1.51 E-02 40 8 2811 1.47 E-02 40 10 3514 6.97 E-03 160 15 5271 1.03 E-03 1560 20 7028 7.75 E-04 2080 25 8785 6.85 E-04 2400 30 10542 4.76 E-04 3520 40 14056 3.03 E-04 5800 50 17570 2.98 E-04 5800 Link: C=622 Mbps (ATM cell transfer rate approx. 600 Mbps) D(msec) B(cells)s(kb^-1) t(msec) -------------------------------------- 1 1415 8.06 E-03 40 2 2830 7.94 E-03 40 4 5660 3.59 E-03 160 6 8490 5.25 E-04 1560 8 11320 5.21 E-04 1560 10 14150 4.04 E-04 2080 15 21226 2.47 E-04 3520 20 28301 1.55 E-04 5800 25 35377 1.56 E-04 5800 30 42452 1.54 E-04 5800 40 56603 9.53 E-05 9880 50 70754 9.59 E-05 9880 References [CSS98] C. Courcoubetis, V.A. Siris, G.D. Stamouli. Application and evaluation of large deviation techniques for traffic engineering in broadband networks. In Proc. of ACM SIGMETRICS'98/ PERFORMANCE'98, Madison, Wisconsin, June 1998. [CW96] C. Courcoubetis and R. Weber. Buffer overflow asymptotics for a switch handling many traffic sources. Journal of Applied Probability, 33, 1996. [Ros95] O. Rose. Statistical properties of MPEG video traffic and their impact on traffic modeling in ATM systems. University of Wuerzburg. Institute of Computer Science Research Report Series. Report No. 101.