As we learned in Chapter 1, the most complicated and interesting component of end-to-end delay is queuing delay. In this applet, you specify the packet arrival rate and the link transmission speed. You'll then see packets arrive and queue for service. When the queue becomes full, you'll see the queue overflow--that is, packet loss.
A particularly interesting case is when the emission and transmission rates are the same, for example when both are 500 packets/sec. If you let the applet run for a very long time, you'll eventually see the queue fill up and overflow. Indeed when the two rates are the same (that is, ρ = 1), the queue grows without bound (with random inter-arrival times), as described in the text.
This applet was designed and coded by David Grangier as part of course work at Eurecom Institute.