Compare for SPR and our routing method

Our simulation compares three methods results, the first is shortest path routing method (SPR), and the second is proportion routing method, finally, we show choose maximum bandwidth routing method result. For all eight sources simulation, we only discuss the results of source 5,7,8 because the results of source 5,7,8 have unique meaning on choosing paths for total network topology.

The following figures show the mean data rate of source 5,7,8 using shortest path routing method. From my simulation, I observe that the original shortest path method makes TCP flow of source 7 having un-uniformly throughput show in the following figures. This means that some flows in source 7 may get bad throughputs because source 7 needs to share bandwidth with source 3,4. For source 5 and source 8, they are show the uniform distribution of throughput in Fig 12 and Fig 14 because no other sources will share their bandwidth on their paths.

Fig 12 Mean data rate of SD pair 5 with SPR method

Fig 14 Mean data rate of SD pair 8 with SPR method

Because the bad result of source 7, we try to use proportion routing method and choose maximum bandwidth method to improve all user’s throughput fairness and let network manger approach maximum utilize buffer of link. These results show as following figures:

Fig 15 Mean data rate of SD pair 5 with proportion routing method

Fig 17 mean data rate of SD pair 8 with proportion routing method

Fig 18 Mean data rate of SD pair 5 with chosen maximum bandwidth method

Fig 19 Mean data rate of SD pair 7 with chosen maximum bandwidth method

In the results of choose maximum bandwidth routing method, it gets more uniform distribution for throughput of each flows of individual source-destination pairs. Individual source-destination pairs get well utilization in each links because we unite routing and adaptive control algorithm.

It looks like that the fairness of choosing maximum bandwidth routing method is better than proportion routing and shortest path routing. However, the global fairness of chosen maximum bandwidth routing is not the best. In order to show the global fairness is really not the best, we compare again the fairness for all source-destination pairs by our global fairness index.

The function of global fairness index is:

∑∑

The table 1 lists results of three methods:

Table 2 Global fairness index of three methods

In the table 2, we can see that the global fairness of proportion routing method is best and chosen maximum bandwidth routing is less about 0.02 percent for global fairness index, shortest path routing is less about 0.2 percent for global fairness index. Form the above results of simulation;

we guess that when the fairness index increases then the throughput of each flow will decrease. In order to prove the phenomenon is rally truly, we also measure the mean throughput for three methods in the table 3.

Table 3 Average throughput of three methods

In table 3, we can see that the mean throughput of SPR is highest, throughput of chosen maximum bandwidth routing lessees about 600 packets per flow than SPR and the worse case is proportion routing, it lessees about 1100 packets per flow than SPR. It shows that if we want to get good global fairness then our total throughput will decrease at the same time.

Chapter 5

Conclusion and Future work

In the thesis we propose two routing methods that unify congestion control and they improve the total fairness among different source-destination pairs. The two methods only base on binary feedback information to configure their routing strategies. According to our simulation, the proportion routing method can achieve to 82 percent for global fairness index. However, the mean throughput will be reduced to about 2900 packets per flow. For this kind of result, we guess that using SPR method does not spent the bandwidth of other TCP flows in their original paths and using proportion routing may spend the bandwidth of other TCP flows cause the throughput of flows decreasing. How to solve this problem is the biggest work for us. For the further research, maybe we can trade off between fairness and throughput by adding some parameters to configure them to approach a balancing situation. The parameters can like as flows number in a path etc.

References

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[3] Anindya Basu, Alvin Lin, Sharad Ramanathan, “Routing Using Potentials: A Dynamic Traffic-Aware Routing Algorithm”, ACM SIGCOMM, August 25-29, 2003.

[4] Sally Floyd, Mark Handley, Jitendra Padhye, “Equation-Based Congestion Control for Unicast Applications: the Extended Version*”, March 2000. ICSI Technical Report TR-00-03, URL http://www.aciri.org/tfrc/.

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IEEE INFOCOM, Mar. 2000, pp. 1166–1175.

[6] F. Bonomi and K. W. Fendick, “The rate-based flow control framework for the available bit rate ATM service,” IEEE Network, vol. 9, no. 2, pp. 25–39, Mar./Apr. 1995.

[7] N. F. Maxemchuk, “DISPERSITY ROUTING”, Proceedings. of ICC, June 1975, pp.

41.10-41.13.

[8] P. Newman, “Traffic Management for ATM Local Area Networks,” IEEE Communications Magazine, pp.44-50, August. 1994.

[9] S. Floyd, E. Kohler, “TCP Friendly Rate Control (TFRC): The Small-Packet (SP) Variant”, April 2007.URL http://www.ietf.org/rfc/rfc4828.txt.

Appendix A

Fig 21 Mean data rate of SD pair 1 with SPR method

Fig 23 Mean data rate of SD pair 3 with SPR method

Fig 24 Mean data rate of SD pair 4 with SPR method

Fig 25 Mean data rate of SD pair 6 with SPR method

Fig 27 Mean data rate of SD pair 2 with proportion routing method

Fig 28 Mean data rate of SD pair 3 with proportion routing method

Fig 29 Mean data rate of SD pair 4 with proportion routing method

Fig 30 Mean data rate of SD pair 6 with proportion routing method

Fig 31 Mean data rate of SD pair 1 with chosen maximum bandwidth routing method

Fig 32 Mean data rate of SD pair 2 with chosen maximum bandwidth routing method

Fig 33 Mean data rate of SD pair 3 with chosen maximum bandwidth routing method

Fig 34 Mean data rate of SD pair 4 with chosen maximum bandwidth routing method

Fig 35 Mean data rate of SD pair 6 with chosen maximum bandwidth routing method

Appendix B

Table 4 Local fairness index of three methods