.
I. - , :
node
switch
router
hub / smart hub
remote access device
dial-up modem
bridge
security
firewall
jukebox
II. , :
destination computer; data transfer; information technology department;
communications network standards; data file transfer; high-speed fiber optic transmissions
III. :
workgroup, redirection, typically, router, incompatible, efficiency, unauthorized, performance
IV. , , "There + to be".
V. " " .
VI. " ":
a) 1. Computer networks allows us to speed up connection between computers.
2. This permits standard circuits to be used throughout the system.
3. The information permitted the properties of the new substance to be predicted.
b) 1. The world knows Babbage's ideas to have had a great influence on the computer development.
2. We saw the printer operate.
3. The assistant made her study all the functions of the computer units.
4. The engineer wanted the new devices to be tested in our laboratory.
VII. - " it ", , , . .
- " it " , :
find , , ;
make .
" it " :
possible
reasonable , , ..
VIII. , - .
IX. " " .
X. " ":
1. Linear programming proved to be especially effective in analysing industrial processes.
2. He happened to know some high level programming languages.
3. ADA turned out to be named after Augusta Ada Byron, the daughter of the English poet, Lord Byron.
4. Programming seems to have several forms.
XI. . , .
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1. There is often need for various devices in a computer network to help facilitate getting data or information through the communications channel, from one computer to another. It all begins with a node, which is any point of connection in a computer network. A node may be the originating computer, the destination computer, any computer in the communications channel through which data or information passes, or any one of a number switches of devices in the channel that help facilitate the data transfer. Most of these switches and devices are designed for different applications for example, the data center in the Information technology department, for a workgroup, or for an individual PC. Here are a few examples:
2. Switches. A switch receives incoming transmissions arriving at a node and redirects them through the network to their proper destinations. Switches typically have a prescribed bandwidth that allows them to handle different volumes of transmissions. There are different switches for different types of networks, such as LANs and WANs.
3. Routers. A router is used in packet-switching networks to examine the packet and its addressing, and determine how to send it on its way to the proper destination.
4. Smart Hub. A hub is any node on a network, but a smart hub replaces separate switches and other network hardware devices that make it simpler to create and maintain networks, such as LANs, or to interconnect incompatible networks, such as a high-speed WAN and a lower-speed LAN.
5. Remote Access Devices. Remote access devices are used to connect remote users to central or enterprise computers and data centres for example, the traveling businessperson using a notebook computer. Remote access devices are special dial-up modems, switches, bridges, routers, hubs, and servers that are designed to ensure security, proper access (to one's workgroup LAN, the corporate database, and so on), with the most speed and efficiency and the lowest cost.
6. Internet Devices. Internets and intranets (within the enterprise) require special communications devices, such as the firewall to ensure security and prevent unauthorized access, special servers for different types of information a CD-ROM jukebox or a video server, for example and routers and switches specially configured for Internet and Intranet uses.
Network Standards
7. Communications network standards are the rules and guidelines for achieving satisfactory performance and communications between different networks and computer systems. Each new communications technology or application seems to require its own standards. Here is a sampling of network standards:
ASCII, for data file transfer
FDDI, for high-speed fiber optic transmissions
TI (and T3) for wideband circuits
SMTP (Simple Mail Transfer Protocol) for electronic mail message handling
SNA for IBM mainframe communications
DECNET, for Digital minicomputer communications
XII. .
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