Figure 6.28 investigates a 12 kbyte file size and Figure 6.29 investigates a 50 kbyte file size, both with constant file size distribution. Both figures compare the simulation results with the calculations of the M/G/R/N-PS model (here N=15) using formula (6.28) and (6.29) for average file transfer delay (left diagram) and CAC reject ratio or blocking (right diagram). The x axis is the offered traffic load including the rejected traffic, as a percentage of the lub user plane capacity (1500 kbps). The results verify that for different file sizes the proposed M/G/R/N-PS model gives correct estimations for the average file transfer delay and the call reject ratio. It is also found that the obtained accuracy is higher with a larger the file size. This is because that the presented M/G/R/N-PS model in this thesis has not considered the TCP slow start effect. For 50kbyte file size, the TCP slow start does not cause significant effect. Thus it can be seen that the calculated average delay for the 50 kbyte file size from the M/G/R/N-PS model matches better to the simulation results than the 12 kbyte file size, as well as the call reject ratio. M/G/R/N PS M/G/R/N PS Simulation with CAC (12kbyte) Simulation with CAC (12kbyte) offered load offered load Figure 6.28: File transfer delay (left), blocking ratio (right): ftp scenario, RAB 128 kbps, CAC reserved rate = 96 kbps, constant file size of 12 kbyte, lub link =1 E1 line 6.3 Dimensioning for Elastic Traffic M/G/R/N-PS M/G/R/N-PS Simulation with CAC (50kbyte) Simulation with CAC (50kbyte) offered load offered load Figure 6.29: File transfer delay (left), blocking ratio (right): ftp scenario, RAB 128 kbps, CAC reserved rate = 96 kbps, constant file size of 50 kbyte, lub link = 1 E1 line The presented example results demonstrate that in case of applying CAC in the transport network for the given traffic, the suggested M/G/R/N-PS model is a correct analytical model to estimate both application performance and connection reject ratio. So that it can be further used for link di