A new adaptive marker for bandwidth fairness between TCP and UDP traffic in DiffServ

The current DiffServ proposal suffers from an unfair distribution of excess network bandwidth among aggregates and also between TCP and UDP flows. To alleviate this problem, in this paper a new time sliding window based marker has been proposed. The improvement in fairness among TCP aggregates is proved to be over a large range of provision level (20% to 90%) compared to the recently proposed Improved TSW based Three Color Marker (ItswTCM) and the Enhanced TSW based Three Color Marker (I2tswTCM) where the range is between 20% to 70% only. This improvement has been achieved by introducing an adaptive factor based on which the yellow packets are marked. The adaptive factor is proportional to CIR and the availability of network resource. In addition to this, the proposed algorithm helps in achieving fairness between TCP and UDP also. The NS-2 simulation results for different network scenarios are furnished. Further, the results confirm insensitiveness to the number of flows in the aggregate.