1. Introduction to Networks Ruth Watson
Chapter 7
Introduction to Networks
Ruth Watson
Operating Systems Concepts 1/e Ruth Watson Chapter 7

2. Operating Systems Concepts 1/e Ruth Watson Chapter 7
Objectives (1 of 2)
Differentiate between a peer-to-peer network and a client server network
Explain the importance of the choice of file system
Differentiate between a client computer and a server
List at least three different server services
Explain the difference between centralized and decentralized administration
Explain the difference between workgroup and domain membership
Operating Systems Concepts 1/e Ruth Watson Chapter 7

3. Operating Systems Concepts 1/e Ruth Watson Chapter 7
Objectives (2 of 2)
Explain why the NTFS file system is more secure than the FAT file system
Define topology
Describe the four main topologies
Differentiate between a network topology and a network technology
Demonstrate how to configure Local Area Connection properties
Describe the role of the network interface card (NIC)
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Introduction
Most professionals work in a Networked environment
Security becomes an issue in a networked environment
When designing networks, there are specific guidelines to follow, such as:
Type of Network
File System
Security
When implementing a network, the physical structure includes:
NIC Cards
Cables
Transmission media
Hubs
Switches
Routers
Operating Systems Concepts 1/e Ruth Watson Chapter 7

5. Important Terms to Understand
Attenuation
Bus
Client/server
Cluster
Ethernet
FAT32
File system
Hub
LAN (local area network)
MAN (metropolitan area network)
Media
Network
NIC (network interface card)
NOS (network operating system)
NTFS
Peer-to-peer
Repeater
Ring
Router
Slack space
Star
Switch
Token Ring
WAN (wide area network)
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Network Scope
Local Area Network (LAN)
Small Network
Usually confined to a building or an office floor
Wide Area Network (WAN)
Two or more LANs connected together
The Internet is an example
Metropolitan Area Network (MAN)
Covers a large area, such as a city
Operating Systems Concepts 1/e Ruth Watson Chapter 7

7. Types of Networks - Peer-To-Peer
Good for small environments, usually up to 10 computers
No dedicated network administrator
Each computer must have specific permissions assigned
Sharing resources can become a problem if the computer with the resource is down
Security is a serious issue
Operating Systems Concepts 1/e Ruth Watson Chapter 7

8. Types of Networks - Client/Server
A server has a special Network Operating system (NOS) to help provide resources to multiple users
Client/Server environments usually have one or more network administrators
Problems can include access, security, and integrity of data
Backups are needed in this environment
Operating Systems Concepts 1/e Ruth Watson Chapter 7

9. Types of Networks - Home Networks
Home networks are becoming more popular
Typically peer-to-peer
Set up is fairly easy
A router keeps track of all the computers inside the home network
Computers are configured with fake IP addresses that allow them to communicate
Operating Systems Concepts 1/e Ruth Watson Chapter 7

10. Centralized vs. Decentralized
Client/Server Environment
Resources are on server
Backup is easier
Profiles are easy to keep track of
Decentralized
Peer-to-Peer Environment
Resources are spread out
There are no profiles
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Workgroup vs. Domain
Workgroup
Peer-to-Peer Environment
Effective for small environments
Security is a problem
Domain
Client/Server Environment
Effective for larger environments
Network administrator has control
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Files Systems
A file system keeps track of files and folders
DOS uses FAT (File Allocation System
Windows 2000 uses NTFS (New Technology File System)
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Choosing a File System
Files systems keep track of files and folders
There are several file systems to choose
A file system determines how files can be named and length of file names
Each operating systems has its own file system
LINUX: ext2 or ext3
Windows 2000: NTFS or FAT32
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Security
How much security you need helps to determine a file system
FAT/FAT32 is good on stand alone computers
NTFS should be used on networks
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Network Topology - Bus
Computers are daisy chained together in a linear bus
Commonly used in the 1980’s
Least expensive
Easiest to setup
Uses coax cable
Data packets are sent along the coax cables
All computers hear data sent out
A BNC connector is used for the NIC card
If there is a break in the computer, the other computers are disturbed
Operating Systems Concepts 1/e Ruth Watson Chapter 7

16. Network Topology - Star
Computers are concentrated into a star pattern using hubs or switches
Most LANs use Star topology
Uses Category 5 cable (cat 6 is on the way)
Cat 5 cable uses an RJ-45 connector for the NIC card
Easy to install
Not that expensive
Hubs broadcast data to all devices
Switches can be used instead of hubs
Switches can help segment data traffic but are more expensive
If there is a break in the cable, it does not disturb the other computers
Operating Systems Concepts 1/e Ruth Watson Chapter 7

17. Network Topology - Ring
Not used as often as the Star
Uses different hardware
More expensive
Complex to install
Best at passing data with less collisions
Operating Systems Concepts 1/e Ruth Watson Chapter 7

18. Network Technology - Ethernet
Ethernet was developed by Bob Metcafe and D.R. Boggs at the Palo Alto Center in the early 1970’s
Multiple cables and protocols can be used with Ethernet
Different networks can be connected, such as:
Windows
Macintosh
Novell
Unix
Operating Systems Concepts 1/e Ruth Watson Chapter 7

19. Network Technology - Token Ring
Token Ring uses a different access method
Only one device transmits at a time
Each device checks to see if the data is for them
Fewer collisions
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Protocols
Protocols are agreed upon rules that networked devices use to communicate
Different organizations came up with different protocols
TCP/IP resolved issues and enabled all computer platforms to communicate
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LAN Components
LAN components include:
Repeaters
Used to amplify data signals due to attenuation
Hubs
Act as a concentrator to connect several computers
Switches
Intelligent hubs that segment traffic to avoid collisions
Routers
Must have to be able to access the Internet
Operating Systems Concepts 1/e Ruth Watson Chapter 7

22. Network Interface Card (NIC)
NIC enables computers to communicate through a unique media access control (MAC) address
The MAC is burned in at the factory
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Summary
You don’t have to be a technology specialist to network your home
Networks range from very small to very large
A server has a special operating system on it that allows multiple users to log in at the same time
Peer-to-Peer networks require no server, but security is an issue
A Client/Server network must have at least one dedicated server and a network administrator
There are four ways to connect your network: bus, star, ring, or hybrid
Protocols are rules that allow computers and other devices to communicate
The most common protocol is TCP/IP
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Questions?
Operating Systems Concepts 1/e Ruth Watson Chapter 7