Networking -- Group of computers connected by cable or other media so they can share information.
Networking Models
|
Centralized |
Distributed |
Collaborative |
| A centralized network is used mostly for large mainframes and terminal computers. All processing and data storage happens at the server. | A distributed network is one in which all of the processing and data storage is performed at the workstation level. | A collaborative network is one in which processing and data storage are spread across machines. More of a client/server model. |
| Advantages: | Advantages | Advantages |
| Ease of backup | Quick access | Extremely fast |
| Security | Multiple uses | Multiple uses |
| Low Cost | Disadvantages | Disadvantages |
| Disadvantages | Virus susceptibility | Susceptible to viruses |
| Slow network access | Backup difficulty | Difficult to back up |
| Fewer options | File synchronization | Difficult file synchronization |
Different Network Types
Peer-to-Peer Networking - In a peer-to-peer network, each workstation acts as both a client and server. Some OS's that support PtoP are Win95, WinNT, Win for Workgroups, and OS/2.
Advantages of PtoP
 |
Inexpensive |
| Easy setup |
| Easy maintenance |
Disadvantages of PtoP
| No central administration |
| Scattered data |
| Evasive resources |
| Weak security |
| Dependent on user training |
Server-Based Networking - Server-based networking is when you have a combination of workstations and servers. If you need user-level security or if you have more than 10 clients than you should use server-based networking.
Advantages of server-based networking
|
Centralized security |
| Dedicated servers |
| Easy accessibility |
| Easy backup |
| Synchronized files |
Disadvantages of server-based networking
| Dependent on an administrator |
| Expensive server |
File Storage and migration
Online storage are files that are readily available on the server at any time.
Offline storage are files that have been backed up onto a tape or other media not accessible.
Near-line storage are files which may have been put on a CD jukebox for availability. Aren't available immediately but are available.
Directory Services - Lets you maintain information about all of the objects in your network. Novell uses NDS (Novell Directory Services and Microsoft will begin using ADS (Active Directory Services).
LAN's, MAN's and WAN's
Local Area Networks - Smallest network, usually confined to a building or a floor. Some characteristics of a LAN are high speed, smaller error counts, and inexpensive price.
Metropolitan Area Networks - Groups of LAN's located in a city. Slower than LAN, but faster than a WAN, expensive and moderate error rates.
Wide Area Networks - Can be as large as worldwide and are usually must slower than LAN speed. They have the highest error rates and the most expensive equipment.