计算机专业英语的课文与翻译之令狐文艳创作

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Unit 8 Computer Networking

Text 1

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Text 2 Data Communications

The end equipmentcan be computers, printers, keyboards, CRTs, and so on.They are either generates the digital information for transmission oruses the received digital data. This equipment generally operates digital information internally in word units.

DTE is data terminal equipment. A station controller (STACO)is the corresponding unit at the secondaries. At one time, the DTE was the last piece of equipment that belonged to the subscriber in a data link system. Between the DTEs, first is the modem, and then

is

the

communications

equipment.

The

communication equipment is owned and maintained by Telco. Data communications equipment (DCE) accepts the serial data stream from the DTE. And DCE converts it to some form of analog signal suitable for transmission on voice-grade lines. At the receive end, the DCE performs the reverse function. It converts the received analog signal to a serial digital data stream.

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令狐文艳创作

The simplest form of DCE is a modem

(modulator/demodulator) or data set. At the transmit end, the modem can be considered a form of digital-to-analog converter.While at the receive end, it can be considered a form of analog-to-digital converter. 参考译文

数据通信

终端设备可以是计算机、打印机、键盘、CRT等。它们可以生成要发送的数字信息，也可以使用所接收的数字数据。这种设备通常在内部以字为单位处理数字信息。

DTE一般称为数据终端设备。辅助设备一方的相应设备是工作站控制器（STACO）。同时，DTE也是数据链路系统中属于用户端的最后一个设备。在两个DTE之间，先是调制解调器，接着是属于Telco电话公司维护的通信设备。数据通信设备（DCE）从DTE接收串行数据流，并将其转换成适合于在语音线路上发送的某种模拟信号形式。在接收端，DCE完成相反的功能，把接收到的模拟信号转换成串行数字数据流。最简单的DCE是调制解调器或数据传送机。在发送端，调制解调器可以视为一种数/模转换器，而在接收端则可视为一种模／数转换器。

Text 3 Architecture of Computer Networks

Computer network is a complex unit, it consists of

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令狐文艳创作

two or more connected computing units. It is used for the purpose of data communication and resource sharing. Design of a network and its logical structure should comply with a set of design principles. They include: the organization of functions, the description of data formats and procedure.

In the following two sections we will discuss two important network architectures, the OSI reference model and the TCP/IP reference model.

(1)

the OSI reference model

The OSI (open systems interconnection) model was created by the ISO. This model is a foundation for comparing protocols; However, more protocols deviate from the rules set up by the OSI model.

The OSI model has seven layers. Note that the OSI model itself is not a network architecture.It just tells what each layer should do. However, ISO has also produced standards for all the layers. Each one has been published as a separate international standard.

(2)

the TCP/IP reference model

TCP/IP is a communication protocol; it provides many different networking services.

The TCP/IP Internet protocol suite is formed from

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