simulation results. The right diagram gives the relative error of the analytical results. It shows that the obtained relative errors (calculated with equation (4.1)) are below 10% in most cases while at high loads (above 90% link utilization) the relative errors get slightly increased (about 11%). page size = 12kbyte (constant distribution) page size = 12kbyte (constant distribution) M/G/R-PS Simulation Figure 6.33: Average application delay over the load for BRA: web scenario, no CAC, page size =12 kbyte, lub link = 1 E1 line The comparison shows that the proposed analytical approach provides an appropriate prediction for average page download delays, though there are some overestimations on the transaction delays in the analytical approach. The overestimation is mainly due to the fact that 6.3 Dimensioning for Elastic Traffic the applied analytical approach does not consider the exact behavior of HTTP 1.1. With HTTP 1.1, during one web session multiple web pages are downloaded over the same TCP connection. That means, except for the first page which is transferred from the beginning with TCP slow start, the second and subsequent pages are transferred over that established TCP connection, which has already been in the fair-sharing state. As a result, the second and subsequent pages need less time to transfer than the first page, since they skip the slow start phase and thus have no degradation on flow performance caused by the slow start. However, the number of pages to download per TCP connection is a statistical variable. The applied analytical approach does not identify pages which do experience the TCP slow start and which do not. Instead, it assumes that each page is transferred with one separate TCP connection including slow start. Therefore, the analytical approach overestimates the overall average transaction time by taking into account the additional delays for the slow start phase for all transactions. This deviation is more noticeable for short flows, for which the duration of the slow start phase is 