Study on the effect of CBR on packet marking in assured forwarding

Many research works have been carried out in differentiated Services, to study the fairness issues between aggregates of both TCP and UDP. Due to multimedia demands, the UDP flows can also demand assured service. Hence, there is a need to protect certain UDP flows which require the same fair treatment as TCP. In such cases, the UDP flows are characterized as AS UDP with target rates and are modeled as CBR sources with fixed traffic rate. In such situations, to study the fairness issue, what should be the CB Rate of the traffic is a question. With a goal to enlighten this, simulations have been carried out with fixed target rates and varying CB rates. The simulations are carried out with the time sliding window based two color marker in NS-2 and their corresponding results being furnished. It is inferred that the CBR should be set at a value greater than the target rate of the UDP source to study its performance and fairness issues.