chapter 1 compter networks and the internetchapter 1 computer networks and the internet.docVIP

Chapter 1 Computer Networks and the Internet 1．The ( ) is a worldwide computer network, that is, a network that interconnects millions of computing devices throughout the world. ppt3 A public Internet 公共网络企业内部互联网交换网引导媒体双绞线铜线同轴电缆纤维光学数字卫星频道地球同步卫星低空卫星纤维光学无线局域网电路交换differ in that ( ). A datagram networks are circuit-switched networks, and virtual-circuit networks are packet-switched networks. B datagram networks are packet-switched networks, and virtual-circuit networks are circuit-switched networks. C datagram networks use destination addresses and virtual-circuit networks use VC. numbers to forward packets toward their destination. D datagram networks use VC. numbers and virtual-circuit networks use destination addresses to forward packets toward their destination. 9．In the following options, which one is not a guided media? ( ) A twisted-pair wire B fiber optics C coaxial cable D satellite 10．Processing delay does not include the time to ( ). A examine the packet’s header B wait to transmit the packet onto the link C determine where to direct the packet D check bit-error in the packet 12．The Internet’s network layer is responsible for moving network-layer packets known as ( ) from one host to another. A frame B datagram C segment D message 13．The protocols of various layers are called ( ). A the protocol stack B TCP/IP C ISP D network protocol 14．There are two classes of packet-switched networks: ( ) networks and virtual-circuit networks. A datagram B circuit-switched C television D telephone 15．Access networks can be loosely classified into three categories: residential access, company access and ( ) access. A cabled B wireless C campus D city area 18．In the Internet, the equivalent concept to end systems is (