- •English For it Students
- •Предисловие
- •Vocabulary:
- •Central Processing Unit (cpu)
- •Vocabulary:
- •Unit 2. Programming
- •Creating Computer Programs
- •Vocabulary:
- •Structured and Object-Oriented Programming
- •Vocabulary:
- •Unit 3. Databases Text 7 Databases and Database Management Systems
- •Database Structures
- •Unit 4. Networks
- •Network Structures
- •Vocabulary:
- •A(an) __________ is a way to connect computers so that they can communicate, exchange information, and share resources in real time.
- •Network Topologies
- •Internet
- •Vocabulary:
- •Unit 5. Information Systems
- •Building Information Systems
- •Vocabulary:
- •Part II
- •Unit 1. Computers around Us
- •Importance of Computer Literacy
- •Shapes of Computers Today
- •Technical Documentation
- •Types of Documentation
- •Computing Issues That Affect Us All Computer Crime
- •Computer Viruses
- •Unit 2. Input, Output, Storage Devices
- •The Mouse
- •Variants of the Mouse
- •Alternative Methods of Input Devices for the Hand
- •Optical Input Devices
- •Audiovisual Input Devices
- •Monitors and Sound Systems Monitors
- •Pc Projectors
- •Sound Systems
- •Printers
- •Types of Storage Devices
- •Magnetic Storage Devices
- •Unit 3. Operating System
- •Types of Operating Systems
- •Windows xp
- •Brief History of Linux
- •Unit 4. Application Software
- •Word Processing Software
- •Desktop Publishing Software
- •Spreadsheet Software
- •Database Management System
- •Presentation Programs
- •Managing the Small or Home Office
- •Working With Images Computer Platforms Used for Graphics
- •Types of Graphics Files
- •Getting Images Into Your Computer
- •Graphics Software
- •Digital Photography
- •Photography the Old Way
- •Multimedia
- •Creating and Distributing New Media Content
- •Technologies That Support New Media
- •Distributing New Media Content
- •Virtual Reality
- •Uses for Virtual Reality
- •Vr Hardware and Software
- •Pc As an Entertainment Center
- •Utility Software
- •Unit 5. Processor and Memory cpUs Used in Personal Computers
- •Universal Serial Bus (usb)
- •Musical Computers
- •Flash Memory and Cache Memory Flash Memory
- •Cache Memory
- •Memory and Computing Power
- •Unit 6. Programming
- •Visual Programming
- •Fourth-generation Programming Languages
- •Artificial Intelligence
- •Some Examples of ai Techniques
- •Building an Artificial Brain
- •Unit 7. Networks and the Internet Networking at Home and Around the World Data Communications Over Standard Telephone Lines
- •Networks in the Home
- •Isdn, t1, and t3
- •Dsl Technologies
- •Avoiding a Tangled Mess
- •From the History of the Internet
- •Getting Online, Working Online Accessing the Internet
- •Connecting a pc to the Internet
- •Commerce on the World Wide Web
- •Getting Published on the Internet
- •Minding Your Manners Online
- •Graphics Piracy on the Internet
- •Ignorance Is No Excuse
- •Staying Out of Trouble
- •Freebies on the Web
- •Personal Web Pages
- •Unit 8. Information Security Protecting Your Online Privacy
- •Macro Viruses
- •Viruses That Do Not Require Attachments
- •Protecting Yourself
- •Vocabulary
- •Литература:
- •Содержание Part I Computer Basics
Avoiding a Tangled Mess
You may think that setting up a network is simple once you have selected the type of network, server, operating system, and other options you need. However, that is only the beginning.
Two of the most time-consuming and costly chores in networking involve choosing the type of wiring that will connect the nodes and servers, and deciding on the most efficient means of running the cable. These issues can be so confusing and costly that many companies have been created to deal with network cabling.
To show how troublesome network cabling issues can become, suppose that you have a warehouse that is 100 feet long and you want to install a network of eleven computers, all lined against one wall. This arrangement places the PCs 10 feet apart, which is the perfect spacing for cubicles.
If you want to use a bus topology, a terminator is placed on the first and last PCs, and ten 10-foot cables are run from one computer to the next. This method means that 100 feet of cable must be purchased and installed.
If you choose a ring or star topology for your network, however, your cabling requirements may increase dramatically. But the additional cabling and equipment (such as a hub) may make your network easier to manage. For instance, it can be easier to add new users to a star network than to a bus network. In such cases, the additional cabling requirements may well be worth the time and expense. Depending on the specific implementation you choose (that is, where you place the hub within the room), your star network may require two or three times more cable than a basic bus network.
There are additional factors to consider. Here are just a few questions networking experts must answer:
Is the network being installed in an existing building, or is it being added to a building under construction? It is always easier to work within a building under construction than to have to drill through walls and run cable in an existing building. For example, many historical buildings such as courthouses have brick walls internally and restrictions (by historical societies) on work that can be done. In such cases, creative alternatives have to be considered.
Can cabling run through the walls or must it run through ceilings? If the cabling will be run through the ceiling, the price of the material triples. Why? Fire codes prevent running ordinary networking cable in places where it can catch fire without being readily seen because of the noxious fumes given off during the burning.
Will conduit be required to encase the cabling? Will you need to use wall plates, wiring closets, and the like?
How much cabling will be exposed? Are there danger zones where people may trip over or drop items on the cabling or connectors?
What if the company wants to be able to rearrange itself on short notice, moving offices, desks, and computers at will? This option can immediately rule out star and bus topologies because the network cannot be brought down every time someone changes an office.
The picture is further complicated when the network must span multiple buildings or several floors of a building.