1. Chapter 1 An Introduction to Networking
Collected and Compiled
By JD Willard
MCSE, MCSA, Network+,
Microsoft IT Academy Administrator
Computer Information Systems Instructor
Albany Technical College

2. Attention: Accessing Demos
This course presents many demos.
The Demos require that you be logged in to the Virtual Technical College web site when you click on them to run.
To access and log in to the Virtual Technical College web site:
To access the site type in the url window
Log in using the username: CIS 1140 or ATCStudent1
Enter the password: student (case sensitive)
If you should click on the demo link and you get an Access Denied it is because you have not logged in to vtc.com or you need to log out and log back in.
If you should click on the demo link and you are taken to the VTC.com web site page you should do a search in the search box for the CompTIA Network+ (2009 Objectives) Course and run the video from within that page.

3. Objectives
List the advantages of networked computing relative to standalone computing
Distinguish between client/server and peer-to-peer networks
List elements common to all client/server networks

4. Why Use Networks?
Network: group of computers and other devices that are connected by some type of transmission media
Commonly connected devices include computers, laptops, mainframe computers, terminals, printers, fax machines, PDAs, cell phones, and various data storage devices
Advantages of networks are that they actually save organizations money by allowing them to:
Centralize Administration
Consolidate (centralize) data storage
Share data and peripheral devices like printers
Increase internal and external communications
Increase productivity and collaboration
Networking Basics Demo

5. Types of Networks Models vary according to: Network models
Computer positioning
Control levels over shared resources
Communication and resource sharing schemes
Network models
Peer-to-peer
Client/server
Network Models Demo

6. Peer-to-Peer Networks
Direct computer communication
Equal authority
Individual resource sharing
Users act as their own administrator
May share resources
May prevent access to resources
Traditional model
Two or more general purpose computers:
Capable of sending and receiving information to and from every other computer
Environments
Small home or office
Large networks using the Internet
Gnutella, Bitcoin, original Napster
BitTorrent software

7. Peer-to-Peer Networks (cont’d.)
Resource sharing method
Modify file sharing controls
User responsibility
Lack centralized control
Access may not be uniform or secure
Resource sharing on a simple peer-to-peer network

8. Peer-to-Peer Networks (cont’d.)
Advantages
Simple configuration
Computers are in same general area
No dedicated server or hierarchy
Less expensive
Compared to other network models
Disadvantages
No centralized storage
Not flexible
Difficult to expand (not scalable)
Not necessarily secure
Decentralized security model
Security is maintained on each individual computer
Not practical for large installations
Usually 10 or fewer workstations
Peer to Peer vs. Server Centric Demo

9. Client/Server Networks
Computer roles
Server
Central computer
Facilitates communication and resource sharing between clients
Clients
Personal computers
Also known as workstations
Run local applications
Store data locally
Use server shared applications, data, devices
Use server as intermediary
Central resource sharing controlled by server
Centralized security model
Sharing data, storage space, devices
No direct sharing of client resources
Communication
Switches or routers

10. Client/Server Networks (cont’d.)
Server requirement
To function as a Server, a computer must be running a network operating system (NOS)
Manages client data, resources
Ensures authorized user access
Controls user file access
Restricts user network access
Dictates computer communication rules
Supplies application to clients
Server examples
UNIX, Linux, Microsoft Server 2008 R2, MAC OS X Server
Server features relative to clients
More memory, processing, storage capacity
Equipped with special hardware
Provides network management functions
Data Redundancy

11. Client/Server Networks (cont’d.)
Disadvantages relative to peer-to-peer network
Complex design and maintenance
Requires extensive advanced planning
Server operating systems are expensive
Advantages relative to peer-to-peer networks
User credentials can be assigned in one place
Multiple shared resource access centrally granted to a single user or groups of users
Centralized backup
Central problem monitoring, diagnostics, correction capabilities from one location
Servers are optimized to handle heavy processing loads and dedicated to handling requests from clients, enabling faster response time
Because of their efficient processing and larger disk storage, servers can connect more than a handful of computers on a network
More scalable
Supports many users
Resource sharing on a client/server network
Client Server and Peer-to-Peer Networks (2:47)

12. LANs, MANs, and WANs LAN (local area network)
Network confined to a relatively small space such as a building or an office
1980s
LANs became popular as peer-to-peer based
Today
Larger and more complex client/server network
High speed networks
Typically Ethernet
Star-wired networks using fiber optic cables, twisted-pair cables, and wireless
Interconnected LANs
LANs and WANs Demo

13. LANs, MANs, and WANs MAN (metropolitan area network) Larger than a LAN
Sometimes called a CAN (campus area network)
Larger than a LAN
Generally covers campuses or office complexes
Connects clients and servers from multiple buildings
Uses different transmission media and technology than LAN

14. LANs, MANs, and WANs (cont’d.)
WAN (wide area network)
Connects two or more geographically distinct LANs or MANs (states, countries, continents)
Uses different transmission methods and media than LAN
Communication circuits connected by routers
Network connection
Separate offices in same organization
Separate offices in different organizations
A simple WAN

15. Elements Common to Client/Server Networks
Network Requirements Demo
Client
Network computer requesting resources or services from another network computer
Client workstation human user
Client software installed on workstation
Server
Network computer managing shared resources
Runs network operating software that can manage not only data, but also users, groups, security, and applications on the network
Workstation
Personal computer
May or may not be connected to network

16. Elements Common to Client/Server Networks (cont’d.)
NIC (network interface card)
Device inside computer
Connects computer to network media
Allows communication with other computers
NOS (network operating system)
Server software
Enables server to manage data, users, groups, security, applications, and other networking functions
A NIC (network interface card)

17. Elements Common to Client/Server Networks (cont’d.)
Host
Computer
Enables network resource sharing by other computers (hosts resources)
Identified by unique network address
Node
Client, server, or other device connected to a network
Connectivity device
Allows multiple networks or multiple parts of one network to connect and exchange data

18. Elements Common to Client/Server Networks (cont’d.)
Segment
Group of nodes
Uses same communications channel for traffic
Backbone
Connects segments and significant shared devices
“A network of networks”
A LAN backbone

19. Computer network physical layout
Topology
Computer network physical layout
Ring, bus, star or hybrid formation
Network Topologies (4:52)
Common network topologies Demo

20. Elements Common to Client/Server Networks (cont’d.)
Protocol
Standard method or format for communication between networked devices
Packet
Distinct data units exchanged between nodes
Addressing
Scheme for assigning unique identifying number to every node on the network

21. Means through which data is transmitted and received
Transmission media
Means through which data is transmitted and received
Examples of network transmission media

22. Summary
A network is a group of computers and other devices that are connected by some type of transmission media
In a peer-to-peer network, every computer can communicate directly with every other computer
A client/server network uses a server to enable clients to share data, data storage space, and devices
A LAN is confined to a relatively small space, such as a building or office

23. Summary
A MAN is larger than a LAN and connects clients and servers from multiple buildings
A WAN connects two or more geographically distinct LANs or MANs
Elements common to client/server networks: client, server, workstation, NIC, NOS, host, node, connectivity device, segment, backbone, topology, protocol, data packets, addressing, and transmission media

24. The End