计算机网络作业一.doc

.Computer Network 2015fallHomework 1作业提交地址： ftp:/ What is the difference between a host and an end system? List several different types of end systems. Is a Web server an end system?答：(1) 基本相同，经常互换。(2) web服务器、PC机、手机、平板电脑。(3) 是的。2. What are the five layers in the Internet protocol stack? What are the principal responsibilities of each of these layers?答：(1) 应用层、运输层、网络层、链路层和物理层。(2) 应用层是网络应用程序及其应用层协议存留的地方；运输层提供了在应用程序端点之间传送应