4 M1000 Mbps Wide Area Network 100 m1

计算机网络的分类网络距离范围速率 4 M~1000 Mbps Wide Area Network 100 m~1 大楼、校 0 km 园 1 km~ 城市 150 km 100~ 国家 1000 km 因特网Internet >1000 km 9. 6 k~256 kbps 局域网LAN Local Area Network 城域网WAN Metropolitan Area Network 广域网WAN 全球 56 k~45 M bps 9. 6 k~45 Mbps

介质共享访问方式 n n 静态方式，如TDMA, FDMA 动态方式： n n 受控方式：统计时分复用S-TDM 随机方式：ALOHA，CSMA Medium Sharing Techniques Static Channelization Dynamic Medium Access Control Scheduling Random Access

Figure 12 -1 OSI Model and Project 802 WCB/Mc. Graw-Hill The Mc. Graw-Hill Companies, Inc. , 1998

Figure 12 -2 Project 802 WCB/Mc. Graw-Hill The Mc. Graw-Hill Companies, Inc. , 1998

IEEE 802. 3 MAC帧格式 802. 3 MAC Frame 7 1 Preamble SD Synch 2 or 6 Destination Address Start frame 0 Single address 1 Group address 0 Local address 1 Global address 2 or 6 Source Address 2 Length Information Pad 4 FCS 64 to 1518 bytes • Destination address is either single address or group address (broadcast = 111. . . 111) • Addresses are defined on local or universal basis • 246 possible global addresses Figure 6. 52

Figure 12 -3 PDU Format WCB/Mc. Graw-Hill The Mc. Graw-Hill Companies, Inc. , 1998

Figure 12 -4 PDU Control Field WCB/Mc. Graw-Hill The Mc. Graw-Hill Companies, Inc. , 1998

Figure 12 -7 MAC Frame WCB/Mc. Graw-Hill The Mc. Graw-Hill Companies, Inc. , 1998

802. 11

Figure 12 -5 WCB/Mc. Graw-Hill The Mc. Graw-Hill Companies, Inc. , 1998

Figure 12 -6 Evolution of CSMA/CD WCB/Mc. Graw-Hill The Mc. Graw-Hill Companies, Inc. , 1998

(a) 以太网的组成传输介质，HUB，网卡，作站 (b) Ethernet Processor RAM ROM RAM Figure 6. 10

CSMA/CD的特性 a = 0. 2 a = 0. 1 a = 0. 01 Figure 6. 51

Single collision domain 共享式与交换式以太网 (a)共享式 High-Speed Backplane or Interconnection fabric (b)交换式 Figure 6. 56

快速以太网的应用 Ethernet Switch Server 100 Mbps links 与服务器的连接采用 100 Mbps快速以太网 Ethernet Switch 10 Mbps links Figure 6. 57

Figure 12 -8 Ethernet Segments WCB/Mc. Graw-Hill The Mc. Graw-Hill Companies, Inc. , 1998

Figure 12 -9 WCB/Mc. Graw-Hill The Mc. Graw-Hill Companies, Inc. , 1998

Figure 12 -9 -continued 10 BASE 5 WCB/Mc. Graw-Hill The Mc. Graw-Hill Companies, Inc. , 1998

Figure 12 -10 Transceiver WCB/Mc. Graw-Hill The Mc. Graw-Hill Companies, Inc. , 1998

Figure 12 -11 WCB/Mc. Graw-Hill The Mc. Graw-Hill Companies, Inc. , 1998

Figure 12 -11 -continued 10 BASE 2 WCB/Mc. Graw-Hill The Mc. Graw-Hill Companies, Inc. , 1998

Figure 12 -12 WCB/Mc. Graw-Hill The Mc. Graw-Hill Companies, Inc. , 1998

Figure 12 -12 -continued 10 BASET WCB/Mc. Graw-Hill The Mc. Graw-Hill Companies, Inc. , 1998

Figure 12 -13 WCB/Mc. Graw-Hill The Mc. Graw-Hill Companies, Inc. , 1998

Figure 12 -13 -continued 1 BASE 5 WCB/Mc. Graw-Hill The Mc. Graw-Hill Companies, Inc. , 1998

Figure 12 -14 WCB/Mc. Graw-Hill The Mc. Graw-Hill Companies, Inc. , 1998

Figure 12 -15 WCB/Mc. Graw-Hill Token Passing The Mc. Graw-Hill Companies, Inc. , 1998

Figure 12 -15 -continued WCB/Mc. Graw-Hill Token Passing The Mc. Graw-Hill Companies, Inc. , 1998

Figure 12 -16 Token Ring Frame WCB/Mc. Graw-Hill The Mc. Graw-Hill Companies, Inc. , 1998

Figure 12 -17 WCB/Mc. Graw-Hill Data Frame Fields The Mc. Graw-Hill Companies, Inc. , 1998

Figure 12 -17 -continued WCB/Mc. Graw-Hill Data Frame Fields The Mc. Graw-Hill Companies, Inc. , 1998

Figure 12 -18 Token Ring WCB/Mc. Graw-Hill The Mc. Graw-Hill Companies, Inc. , 1998

选作的习题 n n n Communication Networks一书中 Problems 4, 5, and 25 on Page 453 You don’t need to send answers to me.

MATLAB简介(3) http: //www. mathworks. com/

OPNET简介(3) http: //www. opnet. com/