Chapter 8 ——Telecommunications, Networks, and the Internet 刘文静 陈晨 田晓君 2010年12月12日

CHAPTER OUTLINE 8.1: Telecommunications and Networking in Today's Business World 8.2: Contemporary Networking Infrastructure 8.3: The Internet 8.4: Technologies and Tools for Communication and E-Business 8.5: Management Opportunities, Challenges, and Solutions

8.1: Telecommunications and Networking in Today's Business World Features: Equipment slowly; Services quickly Technology Development

FIGURE 8-1 transport services (wireless and local exchange), specialized services (Internet backbone and local connections), and support services (wireless, cable, and high-speed broadband services; wireless public networks; enterprise networks).

有七个在电信，你应该知道的主要趋势： 快速的技术革新导致了新的硬件设备和新的替代品增殖业务通信与互联网从手机，到Wi - Fi无线局域网络（在下面的章节中描述）。 继续鼓励竞争的电信放松管制，降低长途电话服务的价格，创造了许多替代品的本地电话服务，如无线，有线以及互联网电话。 电话，有线电视，互联网和卫星电信供应商差别已经为每个类型的网络供应商，旨在提供一个网络视频，语音和数据连接模糊。例如，电话公司正在进入视频传输和编程使用到屋子里，小企业的数字用户线。 越来越多的语音，视频和数据通信网络技术的优势。 快速增长的“最后一英里”高速宽带连接的家庭和企业。今天，有超过一半的美国互联网用户有宽带，电话和有线电视公司提供的访问。在韩国，超过九成的上网人口中有百分之宽带接入（内翻，2004年）。 快速增长的无线电话机，无线计算机网络和移动互联网设备。 越来越多的通信密集的服务和产品，如网络电话和电话摄影，范围。

案例：放松管制的电讯业 大约20年前，美国电话电报公司（AT＆T）的公司提供在美国几乎所有的电信服务，与1934年通信法案获得垄断地位。为了有权提供一个单一的国家电话和电报网络回传，国会规定的价格在AT＆T公司可以收取，并要求普遍服务扩展到全国，包括美国乡村，各地区，“合理的价格。”            在50年代中期开始，美国司法部反托拉斯行动，结束开始在AT＆T的垄断，促进更多的电信竞争。 1982年的法院命令，于1984年实施，分裂成一个长途电话公司和七个独立，区域电话公司（地区性贝尔运营公司，作为RBOCs已知）被下令允许AT＆T公司如Sprint和MCI长途竞争对手本地客户提供服务。为了刺激竞争，法院在制造业，长途和信息服务，同时保留在本地电话管制的垄断。            1996年的电信法，允许发动长途电话公司提供本地服务，并要求RBOCs租用当地一个更深刻的折扣率最后一公里线路的竞争对手更加电信竞争。该法案还允许RBOCs进入长途电话市场。            技术变化和放松管制的综合影响是创建一个更加复杂，多样，竞争的电信环境。

Metcalfe’s Law According to Metcalfe’s Law, the value of participating in a network grows exponentially as the network adds more members.

8.2: Contemporary Networking Infrastructure Networks and Corporate Infrastructure Key Digital Networking Technologies Physical Transmission Media Types of Networks Broadband Network Services and Technologies Theory:NOS操作系统；OSI系统；双绞线，同轴电缆，光纤和无线传输介质 Technology:客户机/服务器计算，包交换的使用，以及广泛使用的通信标准的发展:

8.3: The Internet 互联网寻址，建筑与治理：管理 IP域名系统L;IPV4和IPV6;不同组织和政府机构 互联网服务：应用 互联网和商业价值：应用 万维网：应用 内联网和外联网：应用 下一代网络和互联网：

Section 8.4: Technologies and Tools for Communication and E-Business E-Mail, Chat, Instant Messaging, and Electronic Discussions Groupware, Teamware, and Electronic Conferencing Internet Telephony Virtual Private Networks

Internet Telephony 网络电话 IP电话通话数位化，打破了成数据包，可能沿不同路线的旅行之前，在他们的最终目的地重新组合语音信息。一个最近通话的目的地处理器，称为网关，以正确的顺序排列的数据包，并引导他们到接收器或接收计算机的IP地址的电话号码。 网络电话 IP电话通话数位化，打破了成数据包，可能沿不同路线的旅行之前，在他们的最终目的地重新组合语音信息。一个最近通话的目的地处理器，称为网关，以正确的顺序排列的数据包，并引导他们到接收器或接收计算机的IP地址的电话号码。 14

Virtual Private Networks 虚拟专用网 15

8.5: Management Opportunities, Challenges, and Solutions Management Challenges Solution Guidelines LOSS OF MANAGEMENT CONTROL ORGANIZATIONAL CHANGE REQUIREMENTS SCALABI LITY, RELIABI LITY, AND SECURITY DEVELOPING A STRATEGIC NETWORKING PLAN MANAGING THE CHANGE

Key Terms 1.Asynchronous Transfer Mode (ATM) A technology can handle many types of network traffic and provides transmission speeds ranging from 1.5 Mbps up to more than 9 Mbps 2. Backbone It is the part of a network that handles the major traffic. 3. Bandwidth The range of frequencies that can be accommodated on a particular telecommunications channel is called its bandwidth 4. Bus networks Bus networks are the most common Ethernet topology 5. Cable modems Cable modems are modems designed to operate over cable TV lines 6. Dense wavelength division multiplexing (DWDM) Optical networks can boost capacity by using 7. Digital Subscriber Line (DSL) DSL technologies also operate over existing copper telephone lines to carry voice, data and video, but they have higher transmission speeds than ISDN

8. Domain Name System (DNS) a DNS converts IP addresses to domain names 9. Fiber-optic cable It consists of strands of clear glass fiber, each the thickness of a human hair, which are bound into cables 10. File Transfer Protocol (FTP) 11. Firewalls Whereas the Web is available to anyone ,an intranet is private and is protected from public visits by firewalls 12. Frame relay It is a shared network service that is faster and less expensive than packet Switching 13. Hertz One hertz is equal to one cycle of the medium 14. Hubs Hubs are very simple devices that connect network components, sending a packet of data to all other connected devices 15. Hypertext Transfer Protocol (HTTP) HTTP is the communications standard used to transfer pages on the Web

16. Instant messaging It is a type of chat service that enables participants to create their own private chat channels 17. Integrated Services Digital Network (ISDN) It is an international standard for dial-up network access that integrates voice , data, image, and video services in a single link 18. Local area network （LAN） A LAN is designed to connect personal computers and other digital devices within a half mile or 500-meter radius. 19. Metropolitan area network (MAN) MAN is a network that spans a metropolitan area, usually a city and its major suburbs 20. Network interface card (NIC) Each computer on the network contains a network interface device called a NIC 21. Network operating system (NOS) The NOS routes and manages communications on the network and coordinates network resources. 22. Unifrom Resource Locator (URL) The directory path and document name are two more pieces of information within the Web address that help the browser track down the requested page. Together ,the address is called a URL

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