Adaptive Network Management

Edwin HernandezHCS - Lab June 8th, 1999

Traffic characterization

Hurst parameter provides information about the traffic type in the network

Tests executed using H=0.5 and H=0.8Modification on sampling policies to

increase accuracy in samples.Tradeoff : Accuracy vrs Nr of Samples,

discussed by Klaffy et.al and other papers

Measurements of Self-similarity in traffic patterns used

y = -0.9336x + 0.0414

R2 = 0.986-2.5

-2

-1.5

-1

-0.5

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0.5

0 0.5 1 1.5 2 2.5Log(NormVar)

H=0.5

Linear (Log(NormVar))

To determine the hurst parameter, it is required to use the Log(Variance) vrs Log(granularity) graph. In this experiment theGranularity refers to different sampling times. This method is basedin the property of slowly decaying variance. The relationship is defined by =2H-2, and var(X(m)) am-, as m

H=0.5337, Videoconference data - multimedia traffic

Self-similarity in traffic

y = -0.3726x + 0.0032

R2 = 0.9437-2.5

-2

-1.5

-1

-0.5

0

0.5

0 0.5 1 1.5 2 2.5Log(NormVar)

H=0.5

Linear (Log(NormVar))

H=0.8137, TCP Traffic using as source Fractional Gaussian Noisetool (by Vern Paxon, et.al. UCB). Traffic stimulation between hornetand raptor.

Results for Adaptive samplers

Hurst Method Number of Samples Average Variance STDev MAX MIN0.8 Systematic Sampling (Ts=1s) 3600 416544.5 16863275404 129858.7 1068461 58830.8 Filter O(2) 1852 407298.7 13216398817 114962.6 1223451 77440.8 Filter O(3) 856 383969 11225787824 105951.8 733612 120480.8 Filter O(4) 596 378376 11762723717 108456.1 623401 117110.8 Fuzzy Logic Controller 3365 412254.2 15467361344 124367.8 949919 9795

Hurst Method Number of Samples Average Variance STDev MAX MIN0.5 Systematic Sampling (Ts=1s) 3600 280852.7 8.34901E+11 913729.4 11613106 00.5 Filter O(2) 1545 322924.4 7.40771E+11 860680.7 10128443 00.5 Filter O(3) 1428 316285.7 6.48586E+11 805348.3 8825943 00.5 Filter O(4) 1254 302533.8 6.3696E+11 798097.7 9885448 00.5 Fuzzy Logic Controller 1358 287494 4.72594E+11 687455.0 6463903 0

Results using the previous policies.The problem is presented with H=0.5, where the STDev is 3.2 timesthe average value. High frequency components lost. With H=0.8, The STDev is only 0.31 of the average value.

Throughput with H=0.8

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Systematic sampling at T=1s

throughput with FLC

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Throughput with filter of O(2)

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Throughput with filter O(4)

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ConclusionsO(n) controllers does not work if N is

increased and H=0.8, with the exception of O(2)

Substitute in 0.1*Tmax for a 10 seconds interval.

FLC works pretty well with H=0.8, but the decrease in samples is only 12%

O(n) and FLC performs similarly with H=0.5 or multimedia traffic

Conclusion

Some accuracy will be lost if we increase the granularity or sampling time.

Hurst parameter not easy to calculate, requires time and a lot of samples.