Local Area Networking

This article defines computer networking and gives a simple explanation of how data is transmitted on a network. It explains the benefits of networking computers and their advantages and disadvantages.

Part 1: Networking Intro

Definition

(Andrews, p.896; McFredries, p.982)

Networking is a means of connecting computers together so that they can share resources, such as files and peripherals (printers, modems, CD-ROM drives, etc.) and services.

Networking involves using both hardware and software.

Sharing

File and Secondary Storage

  • Word processing and spreadsheet files
  • Large databases (inventory, accounting, customer base)

Peripherals

  • Printers
  • Modems
  • CD-ROM drives

Network Applications

  • Electronic mail
  • Groupware (Scheduling and Project Management)
  • Database applications such as Point of Sales

Administrative Services

  • Security
  • Installation/configuration
  • Backup

Advantages

Besides the convenience of making information easier to share, the advantages are chiefly economic and administrative.

  • Sharing peripherals makes them accessible without having to purchase them for each and every machine.
  • Backup of critical information is more convenient when it is centrally-located in common storage areas,
  • Access to sensitive information can be controlled using network security features
  • User interfaces can be standardized, leading to reduced training and support
  • Applications can be installed and configured centrally, saving time and effort

Disadvantages

  • Reduced performance - file access slower
  • Less flexibility for individual users
  • Administration becomes more difficult as networks become large and complex

Transmission of Data

Data is transmitted across the network in the form of bits and bytes translated into electrical signals (each bit being on or off, or positive or negative).

Before being transmitted, bytes are arranged into segments for transmission over a network. Each segment of data is attached to a header and a trailer.

  • The header precedes the data and identifies the data's destination and the protocols used by the packet.
  • The trailer follows the data and is used by some protocols for error checking.

The header and trailer are referred to as a frame and the entire package, frame and data, is called a packet.

Packets are transmitted (as bits and bytes) separately over the network.

At the receiving end, the headers and trailers are removed and the data from all the packets is reassembled into contiguous data.

On a PC, the process of breaking data down into packets and then reassembling them is carried out by the firmware on the network interface card.


Bruce Miller, 2002