Transcript Chapter 1 An Introduction to Networking

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
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 www.vtc.com in the url window
– Log in using the username: CIS 1140 or ATCStudent1
– *Enter the password: student
• 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.
*Remember that passwords are case sensitive so enter it in all
lower case letters.
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
Why Use Networks?
• Network: group of computers and other devices that are
connected by some type of transmission media
• Commonly connected devices include microcomputers,
minicomputers, mainframe computers, terminals,
printers, fax machines, pagers, and various data storage
devices
• Advantages of using networks over standalone
computers:
– Networks enable multiple users to share the
network’s resources (devices and data)
– Networks allow you to manage, or administer,
resources on multiple computers from a central
location
What Is A Network Demo
What Are the Benefits of Computer
Networking?
• Powerful, Flexible Collaboration
• Cost-Effective Resource Sharing
• Secure Management of Sensitive
Information
• Effective Worldwide Communications
• Easy, Immediate Information
Dissemination
• Worldwide, Instantaneous Access to
Information
Types of Networks:
Peer-to-peer Networks
• Simple to configure and relatively inexpensive
• Every computer can communicate directly with every
other computer
• By default, no computer has more authority than another
• No centralized security. Security is maintained on each
individual computer (decentralized security model)
• Every computer is capable of sending and receiving
information to and from every other computer
Network Models Demo
Peer-to-peer Networks
•No dedicated server or
hierarchy, also called a
workgroup.
•NUsually 10 or fewer
workstations. ot very
flexible or scalable.
•Users act as their own
administrator and security
which makes them relatively
unsecure.
•Computers are in same
general area.
•Limited growth.
Resource sharing on a simple peer-to-peer network
Peer to Peer vs. Server Centric Demo
Client/Server Networks
• The most popular type of network for medium- and large-scale
organizations
• Client/server network: uses a server to enable clients to share data,
data storage space, and devices
• Server: central computer used to facilitate communication and
resource sharing between other computers (called clients) on the
network (centralized security model)
• To function as a Server, a computer must be running a network
operating system (NOS)
– Manages data and other resources for a number of clients
– Ensures only authorized users access the network
– Controls access to resources
– Restricts when and from where users can access the network
– Supply applications to clients
Client/Server Networks
•10 or more users.
•Employs specialized
servers.
–File and Print
–Application
–Mail
–Fax
–Communications
(gateways)
•Central administration.
•Greater security.
•Centralized backup.
•Data Redundancy.
•Supports many users
Resource sharing on a client/server network
Client/Server Networks
• Advantages of using client/server networks over
peer-to-peer networks:
– User logon accounts and passwords can be assigned
in one place
– Access to multiple shared resources can be centrally
granted to a single user or groups of users
– Problems can be tracked, diagnosed, and often fixed
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
LANs Local Area Networks
Network Categories Demo
• Local area network (LAN): confined to a relatively small
space, such as a building or an office
• Typically connects computer in a single building or
campus.
• Developed in 1970s.
• Medium : optical fibers, coaxial cables, twisted pair,
wireless.
• High speed networks
• Typically buses or rings.
• Ethernet, Token Ring
MANs Metropolitan area
network
• Larger than a LAN; connects clients and
servers from multiple buildings
• Generally covers campuses or office
complexes
– Connects clients and servers from multiple
buildings
• Developed in 1980s
• Medium : optical fibers, twisted pair cables
• Data rates adequate
WANs Wide area network
• Connects two or more geographically
distinct LANs or MANs
• Developed in 1960s.
• Generally covers large distances (states,
countries, continents).
• Medium : communication circuits
connected by routers.
• Routers forwards packets from one to
another following a route from the sender
to the receiver. Store-and-Forward
• Hosts are typically connected (or close to)
the routers
LANs, MANs, and WANs
A simple WAN
Elements Common to Client/Server Networks
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Client
– A computer on the network that requests resources or services from another
computer on a network.
Server
– Run operating software that can manage not only data, but also users, groups,
security, and applications on the network
Workstation
– A personal computer which may or may not be connected to a network.
Network interface card (NIC)
– The device inside a computer that connects a computer to the network media
NOS
– Software that runs on a server and enables the server to manage data, users,
groups, security, and applications on the network
Host
– A computer that enables resource sharing by other computer on the same network
Node
– A computer or other device connected to a network
Connectivity device
– a specialized device that allows multiple networks or multiple parts of one network
to connect and exchange data
Network Requirements Demo
Elements Common to
Client/Server Networks
A NIC
Elements Common to Client/Server Networks
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Segment
– Usually composed of a group of nodes that share the same
communications channel for all their traffic
Backbone
– The part of a network to which segments and significant shared devices
connect.
Topology
– The physical layout of a computer network
Protocol
– A standard method or format for communication between networked
devices
Data packets
– The distinct units of data that are exchanged between nodes on a
network
Addressing
– The scheme for assigning a unique identifying number to every node on
the network
Transmission media
– The means through which data is transmitted and received
Elements Common to
Client/Server Networks
A LAN backbone
Elements Common to
Client/Server Networks
Common network topologies Demo
Elements Common to
Client/Server Networks
Examples of network transmission media
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
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
The End