软题库 培训课程
当前位置:信管网 >> 在线考试中心 >> 网络工程师题库 >> 试题查看
试卷年份2004年下半年
试题题型【单选题】
试题内容

Networks can be interconnected by different devices.In the physical layer,  networks can be connected by  (1)  or hubs, which just move the bits from one network to an identical network. One layer up we find bridges and switches, which operate at data link layer. They can accept  (2) , examine the MAC address, and forward the frames to a different network while doing minor protocol translation in the process. In the network layer, we have routers that can connect two networks, If two networks have  (3)  network layer, the router may be able to translate between the packer formats. In the transport layer we find transport gateway, which can interface between two transport connections.Finally, in the application layer, application gateways translate message  (4) . As an example, gateways between Internet e-mail and X.400 e-mail must  (5)  the e-mail message and change various header fields.
(1)A、repeaters
B、relays
C、connectors
D、modems
(2)A、frames
B、packets
C、packages
D、cells
(3)A、special
B、dependent
C、similar
D、dissimilar
(4)A、syntax
B、semantics
C、language
D、format
(5)A、analyze
B、parse
C、delete
D、create

查看答案

相关试题