这个简单的程序说明了计算机网络中最基本的概念之一：传输时延与传播时延的比较。虽然这个概念在第一章已详细的讨论过，但一个交互式的动画可以更形象地说明这一点。你设置好链路长度，数据包大小和传输速度后，该实验可以向你演示数据包从发送端向接收端的传播过程。注意有许多种组合，在发送端还没有结束传播过程时分组的头部已到达接收端。 -This simple program illustrates the computer network in one of the most basic concepts: transmission delay and propagation delay of the comparison. While the concept has been in the first chapter discussed in detail, but an interactive animation can be more vividly illustrate this point. You set up the link length, packet size and transmission speed, the experiment can show you the data packets from the sender to the receiver of the communication process. Note that there are many combinations, the sender is not over the head of the communication process when the group has reached the receiver.