随着基于WWW的应用的飞速发展,人们愈来愈依赖于网络获取知识,了解信息,这使得Internet的用户成指数级爆炸式地增长。其中一个负面影响就是网络速度愈来愈慢,人们在获取知识之前不得不忍受严重的时延。时延的产生通常有以下几个原因:①由于服务器的负载过重,从而减缓了对客户的响应。②客户端不能及时处理从网络传输过来的数据。③网络拥塞,从而延缓了对数据的转发。 With the rapid development of WWW-based applications, people increasingly rely on the Internet for knowledge and information, which has exponentially increased Internet users. One of the negative effects is that the network is getting slower and slower, and people have to endure serious delays before they can gain knowledge. There are several reasons for the delay: 1) The response to customers is slowed down due to overloaded servers. ② client can not handle the data transmitted from the network in time. ③ network congestion, thus delaying the data forwarding.