计算机网络学习资料,共20章，分为五大部分。前面第1章引言，内容涉及网络的分类以及网络体系结构和ISO/OSI参考模型-computer network study, a total of 20 chapters, divided into five major sections. In front of Section 1 Introduction, which relates to the classification of network and network architecture and the ISO / OSI reference model