正确答案: D

Packet

题目：() switching was invented in the late 1960s for data communications.

解析：C

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举一反三的答案和解析：

[单选题]贯彻“谁使用、()、谁负责”的原则，切实加强特种设备日常使用环节的监督检查，严禁以包代管

谁管理，

[多选题]SMS一般具备（）等功能。

业务逻辑管理

业务故障

网络配置管理

解析：ACD

[单选题]下一代网络是（）驱动的网络。

业务

[多选题]【A popular service that has attercted the interest of companies and has home users alike is the sending of voice signals over an IP-based network, such as the Internet. The practice of making telephone calls over the internet has had a number of different names, including packet voice, voice over packet, voice over the internet, internet telephone, and Voice over Ip（Voip）. But it appears the industry has settled on the term”Voice ove IP” in reference to the internet protocol, which controls the transfer of data over the internet. There are currently three ways to deliver VoIp to users, the first technique is found at the corporate level. Many companies are offering VoIP systerms that operate over a local area network. These systems involve a fair amount of equipment, such as VoIP servers, special IP-enabled telephones, and routers that can direct telephone calls. Today a large portion of corporate sites have converted their older internal telephone systems to VoIP systems that opreate over a LAN, thus converging two systems into one. A second common solution is the one often encountered at home. Using existing telephones, a special converter is added between the telephone and a high speed internet（DSL or cable modem）connection. The converter digitizes the voice signal and creates a stream of packets that are then sent over an ip connection.The third technique involves smart cell phones. Never cell technologies are all packet-based, thus requiring a telephone call to be converted to digital packets and sending those packets over IP networks.】From the paragraph above，a popular service that has attracetd the interest of companies and home users,is termed as （） . The data transfer over the Internet is controlled by the （） . At corporate level, many companies have replaced their older internal telephone systerms with （） that oprerate over a local area network.

voice over the internet B、voice over packet

Voice over IP

industry

VoIP servers

解析：C,B,A

[多选题]大唐TDB18AE支持哪些类型的天线?()

智能天线

单天线

双极化天线

解析：A, B, C

[单选题]关于国际电话网，（ ）的叙述是不正确的。

国际电话网采用三级树型网络结构，用于疏通不同国家间的长途话务

[多选题]保持应急通信设备完好，应该做到()。

日常维修保养为主

大修更新为辅

解析：A, B

[单选题]终端设备与交换设备之间传送的信令统称为（）。

用户线信令

[单选题]智能外设是受()的控制.

业务控制点