●Networks can be interconnected by different devices in the physical layer networks can be connected by _(66)_ 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 _(67)_ examine the MAC address and forward the frames to a different network while doing minor protocol translation in the process in me network layer ,we have routers that can connect two networks, If two networks have _(68)_ 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 _(69)_ .As an example, gateways between Internet e-mail and X.400 e-mail must _(70)_ the e-mail message and change various header fields.

试卷相关题目

• 1●以下不属于中间件技术的是 _(65)_ 。

  A.javaRMI

  B.CORBA

  C.DCOM

  D.JavaApplet

  开始考试点击查看答案
• 2●将双绞线制作成交叉线(一端按EIA/TIA 568A线序，另一端按EIA/TIA 568B线序)，该双绞线连接的两个设备可为_(64)_。

  A.网卡与网卡

  B.网卡与交换机

  C.网卡与集线器

  D.交换机的以太口与下一级交换机的UPLINK口

  开始考试点击查看答案
• 3●许多网络通信需要进行组播，以下选项中不采用组播协议的应用是 _(62)_。在IPv4中把_(63)_类地址作为组播地址。

  A.VOD

  B.Netmeeting

  C.CSCW

  D.FTP

  开始考试点击查看答案
• 4●以太网100BASE-TX标准规定的传输介质是_(61)_ 。

  A.3类UTP

  B.5类UTP

  C.单模光纤

  D.多模光纤

  开始考试点击查看答案
• 5●以关键字比较为基础的排序算法在最坏情况下的计算时间下界为O(nlogn)。下面的排序算法中，最坏情况下计算时间可以达到O(nlogn)的是_(59)_；该算法采用的设计方法是_(60)_。

  A.归并排序

  B.插入排序

  C.选择排序

  D.冒泡排序

  开始考试点击查看答案
• 6● The purpose of the requirements definition phase is to produce a clear, complete, consistent, and testable _(71)_ of the technical requirements for the software product.During the requirements definition phase, the requirements definition team uses an iterative process to expand a broad statement of the system requirements into a complete and detailed specification of each function that the software must perform and each _(72)_ that it must meet. The starting point is usually a set of high level requirements from the _(73)_ that describe the project or problem.In either case, the requirements definition team formulates an overall concept for the system and then defines _(74)_ showing how the system will be operated publishes the system and operations concept document and conducts a system concept review (SCR).Following the SCR, the team derives _(75)_ requirements for the system from the high level requirements and the system and operations concept. using structured or object-oriented analysis. the team specifies the software functions and algorithms needed to satisfy each detailed requirement.

  A.function

  B.definition

  C.specification

  D.statement

  开始考试点击查看答案