Data Communications and Networking Forouzan Fourth Edition 第9章 使用电话网和有线电视网 进行数据传输 9.1 CopyrightThe McGraw-Hill Companies,Inc.Permission required for reproduction or display
9.1 第9章 使用电话网和有线电视网 进行数据传输 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display
-1 TELEPHONE NETWORK Telephone networks use circuit switching. The telephone network had its beginnings in the late 1800s. The entire network,which is referred to as the plain old telephone system (POTS),was originally an analog system using analog signals to transmit voice. Topics discussed in this section: Major Components LATAS Signaling Services Provided by Telephone Networks 9.2
9.2 9-1 TELEPHONE NETWORK Telephone networks use circuit switching. The telephone network had its beginnings in the late 1800s. The entire network, which is referred to as the plain old telephone system (POTS), was originally an analog system using analog signals to transmit voice. Major Components LATAs Signaling Services Provided by Telephone Networks Topics discussed in this section:
Figure 9.1 A telephone system Local loop Trunk Trunk End Tandem offices offices Regional offices 9.3
9.3 Figure 9.1 A telephone system
Note LATA:Local access and transport area ● LATA可以是一个城市地区或者大城市 提供LATA内部服务被称为本地交换电信 公司(local exchange carriers,LEC) ● 1996年以后，有多个运营商可以提供 LATA内部服务. 9.4
9.4 LATA: Local access and transport area LATA可以是一个城市地区或者大城市 提供LATA内部服务被称为本地交换电信 公司(local exchange carriers，LEC) 1996年以后，有多个运营商可以提供 LATA内部服务. Note
Figure 9.2 Switching offices in a LATA Tandem (toll)offices_ End offices Local loops 9.5
9.5 Figure 9.2 Switching offices in a LATA