主要介绍计算机通信网的基本概念和基本原理，以OSI参考模型为基础，全面系统地讲述分层次的网络体系结构，包括数据链路层、介质访问控制、网络层、传输层和应用层。鉴于TCP/IP是目前被广泛接受的标准，所以兼顾OSI和TCP/IP两大体系，阐述它们的共性问题。内容涵盖了局域网、广域网、互联网（以Internet为典型）、ATM和B-ISDN等网络体制，突出通信子网与资源子网的概念，详细讨论用于计算机通信的各类通信交换技术，并尽可能反映较新的进展，同时也重视必要的理论分析，比如路由选择和流量控制等问题。 本教学内容的主要特点是：1. 讲授始终以基本概念和基本原理为主,对具体协议及其细节加以简化。2. 将用于计算机通信的各类通信网络及相应的交换技术原理单独设章(第三章),以突出通信子网和资源子网的概念。3. 把以OSI/RM为基础的协议分层原理单独设章(第二章)，这种分层原理事实上可以看成所有分层式协议的一般原理。4. 强调了网络互联及其基本原理，网络互联技术是使Internet不断延伸和扩展的基础。5. 兼顾OSI和TCP/IP两大协议体系，力图表述它们的共性问题。

This course covers the basic concepts and principles of computer communication networks. The network architecture is discussed in detail based on OSI referrence model, including data link layer, medium access control, network layer, transport layer and application layer. Meanwhile, this course takes TCP/IP in consideration owing to wide use of Internet. Therefor, the common issues are presented giving attention to two models of OSI/RM and TCP/IP. The content includes LAN. WAN, Internet, ATM and B-ISDN, giving prominence to communication subnet and resource subnet. It also specifies many kinds of switching techniques, thinking much of theoretic analysis, such as routing and flow control, etc.Course Contents and Outline:Chap.1 Introduction1.1 Computer Communication and Computer Communication Networks1.2 Network Hardware1.3 Network Protocols and Architectures (LAN, MAN, WAN, internet)1.4 Design IssuesChap.2 Principle of Layered Protocols2.1 Basic Concepts (OSI/RM, Real Open System, Service, Interface, Protocol)2.2 Principle of Layered Architecture2.3 Networking and its Operations2.4 Data Transportation2.5 Service Primitive2.6 Principle of the Layered OSI/RM Architecture2.7 Comparison of OSI and TCP/IPChap.3 Modern Communication Networks and Switching Techniques3.1 Telephone Networks and Circuit Switching3.2 Data Networks and Packet Switching3.3 The Optimized Packet Length in a Packet-switched Network3.4 Introduction to other Communication Networks (PSPDN, DDN, Frame Relay Network, B-ISDN, ATM, Wireless Networks)3.5 The Physical Interfaces of Computer Communication NetworksChap.4 Data Link Layer4.1 Design Issues for Data Link Layer (Service, Frame, Error Control, Flow Control)4.2 Principles of ARQ (Stop-and-Wait, Go-Back-N, Selective Repeat Request)4.3 Congestion Control using Sliding Window4.4 Describing Method of Protocols4.5 Examples (HDLC, PPP)Chap.5 Media Access Control5.1 Assignment of Broadcasting Channel (Static: FDM, TDM, WDM; Dynamic: ALOHA, CSMA)5.2 Polling Technology (Roll-call, Hub)5.3 Random Access: ALOHA and Slot ALOHA5.4 Random Access: CSMA5.5 Collision-free Protocols5.6 Introduction to IEEE 802 StandardsChap.6 Routing and Congestion Control6.1 Introduction6.2 Routing Algorithm6.3 Congestion Control (Cause, Relationship with Flow Control, Throughput)6.4 Congestion Control in ATM6.5 Congestion Control in TCPChap.7 Internetworking7.1 General Concepts in Internetworking7.2 Network Bridge7.3 Router and Gateway (CCITT X.25, ITU-T X.75, IP Protocol)7.4 Route Selection of InternetChap.8 Transport Layer8.1 Basic Concepts in Transport Layer8.2 Special Problems (Error Control, Connection Management, Timeout and Congestion Control)8.3 Transport Service8.4 Transport Protocols (TCP, UDP)Chap.9 Applications in High Layers of Computer Communication Networks9.1 Introduction (High Layers in OSI, Application Layer in Internet, Data Security, Network Management, DNS, ASN.1)9.2 Application Service Element in OSI (CASE and SASE)9.3 ASN.19.4 Examples: MHS, Directory Service (SMTP, DNS)9.5 Other Examples: FTAM, FTP, Telnet, WWW, HTTPAssessment:Student should grasp the fundamental concepts, principles and algorithms of computer communication networks; he/she should be creative and able to analyze new techniques.The final is a close-book, close-note, 2-hour exam. It consists of short essay-problems, calculating problems, proof problems, and graph problems.