This document provides an introduction to computer networks. It defines networking concepts such as local area networks (LANs) and wide area networks (WANs). It discusses the basic elements needed to build a network, including a medium to carry data, network interface cards, and networking protocols. It also summarizes the two main types of networks: peer-to-peer networks and server-based client-server networks. Server-based networks are preferable for networks with many users or the need for centralized security, administration and access to resources.

1. Introduction to
Networks
Networking Concepts
IST-200
VWCC
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2. What is Networking?
Connecting computers
to form a
Local Area Network
( LAN )
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3. Device Sharing
Sharing of:
Hardware
Software
Information
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4. A Simple Network
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5. Local & Wide Area
Networks
Early networks were custom built
Connecting a dozen computers
Only 1 or 2 peripherals
Early Ethernet
30 users
total span of 601 feet
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6. Local Area Network
(LAN)
A single collection of machines &
peripherals
Generally less than 1000 computers
“Spanned” generally less than 250
meters feet
Basic building block for larger
networks-Internetworks
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7. InterNetworks
IntraNetworks
A network of networks
A networked collection of LANs
More than one floor in a
business (intranetwork)
Multiple buildings
Campus environment
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8. Wide Area Networks
(WAN)
Spans miles of distance
Two or more separate locations
Down the road or across the
world
Microsoft, Federal Express
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9. The Internet
A WAN internetwork
Millions of machines worldwide
The World Wide Web (WWW)
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10. Networking
Terminology
Client/Server relationship
Client requests shared
resources
Server responds & shares
resources
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11. Networking
Terminology
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12. Client Server
Networks
Concentrate CPU power & storage
capacity
Windows NT Server / Server 2000
Peer to Peer
Client/Server role interchanges
Windows 95/98/2000/XP
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13. Simple Network Needs
Medium to carry data
Adapter (NIC)
Protocol
Client / Server Software

14. Local Network
Medium (media)
Carries network messages
Connects machines together on
network
Four types:
 Metallic cable coaxial - dated
 Twisted pair
 Fiber optic cable
 Wireless
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15. Network Interface
Card
(NIC)
Physical link between machine
& network
Connection between machine &
medium
Also known as network adapter
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16. Network Protocols
Common set of communication rules
Identify ‘oneself” & others on network
Interpret signals
Begin & end network communication
Manage network information exchange
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17. Protocol Examples
TCP/IP
for the Internet
IPX/SPX & NWLINK
for Novell
NetBEUI
for Microsoft
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18. Windows Client Setup
Control Panel
Networking
Protocols
Clients
Adapters

19. Network Software
Programs that access the network
Network Operating System (NOS)
Windows NT
Novell NetWare (IntranetWare)
Consist of client & server
components
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20. Network Layers
Network Applications ( NOS &
client)
Instruct network medium
Using machines interface (NIC)
Address & exchange information
To other machines on LAN or WAN
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21. Layers of the
Network
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22. Network Types
Peer to Peer
Windows 98/2000
Windows for Workgroups
Client Server (server-based)
Windows NT
Novell
Unix / Linux
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23. Peer to Peer
No centralized control
Act as both client & server
User controls access to machine
Institutionalized chaos & security
concerns
Adding machines slows network
down
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24. Peer to Peer
Advantages
Easy to install & configure
Users control individual shared
resources
Inexpensive to purchase & operate
No Network Administrator
Best for 10 or fewer users
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25. Peer to Peer
Disadvantages
Security for only a single resource
at a time
Users may need to know many
passwords
Individual machine backups
Speed decreases while sharing
No central location/access of data
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26. Server Based
Networks
Server is the key to this type
Centralized control of resources
Utilize faster processors
More memory
Extra peripherals
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27. Server Security
Physical access to the server
Specialized sentry servers
Domain model
Account names
Passwords
Firewalls
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28. Server Based
Advantages
Central security/ accounts/ access
Simplify network administration
Powerful/ efficient access to
resources
Single password for each user
Best for high use, user, networks
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29. Server Based
Disadvantages
Server failure results in unusable network
Server failure results in loss of resources
Expert staff to manage increases cost
Dedicated hardware increases cost
Dedicated software increases cost
All disadvantages may be overcome
with $$$
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30. Hybrid Networks
Combination networks
Windows 95/98/2000
Windows NT Server/Server
2000
Windows NT Workstation
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31. Server Hardware
Requirements
High Speed Drives –Mirrored or
RAID
512 MB Memory Minimum
High Quality NIC(s)
High-end Processor(s)
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32. Specialized Servers
Individual services supplied
Application Servers
Communication Servers
Domain Controllers/Directory
Servers
Fax Servers
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33. Specialized Servers
(cont.)
Mail Servers
Web Servers
File & Print Servers
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34. Application Servers
Server side of Client/Server
applications
Supply application services and
data
Provide processing services
Microsoft SQL Server runs on
Windows NT Server
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35. Communication
Servers
Access beyond networks local scope
Inbound & outbound resource access
Dial in via modem
Windows NT server Remote Access
Server
(RAS) manages dial in network
connections
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36. Domain Controllers/
Directory Servers
Locate, store, & secure information
about network
Allows computers, users, groups, &
resources to be combined into
domains
Domain access allows single login
to all allowed resources
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37. Fax Servers
Manage network fax traffic
Receive incoming telephone
faxes
Distribute to network users
Collect outgoing network faxes
Send outgoing telephone faxes
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38. File and Print Servers
File storage & File retrieval
Access to network printers
Applications run locally
Store data on server
Window NT server is capable
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39. Mail Servers
E-mail for network users
Allow local exchange of messages
Permit server based storage of
messages
Forward user messages to
destination
Microsoft Exchange Server
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40. Web Servers
World Wide Web (WWW)
File Transfer Protocol (FTP)
Gopher services
Intranets
NT Server Internet Information
Server (IIS)
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41. Selecting the Right
Network
Budget considerations, number of
users?
Physical span of the network?
Specialized servers, services desired?
Internetwork or WAN access?
Future growth?
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42. Summary
Basic elements to build a network
 Medium, physical interface, protocol
 Networking software-client & server
Basic network types
 Peer to Peer
 Server based
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