The traffic generation rate can be modified by changing application properties. Note that the generation rate should be less than or equal to the service rate for steady-state simulation, where the service rate is defined as the data rate supported by the Bottle-neck link. (Users can refer to the queuing theory experiment from experiment manual available at to understand this better)

Now the CBR (Constant Bit Rate) application generates a constant rate of traffic. In this increasing packet size increases generation rate while decreasing Inter-arrival time increases the generation rate. The formula for generation rate is

Generation Rate(Mbps) = ( (Packet size(bytes)∗8)) / (Inter_arrival_time(µs) )

Also, refer