Chapter 1
Living in a Network Centric
World
CIS 81 Networking Fundamentals
Rick Graziani
Cabrillo College
graziani@cabrillo.edu
Last Updated: 2/11/2008
This Presentation
 For a copy of this presentation and access to my web site for other
CCNA, CCNP, and Wireless resources please email me for a
username and password.
 Email: graziani@cabrillo.edu
 Web Site: www.cabrillo.edu/~rgraziani
2
Overview
Remember, we are just beginning to herd the cats.
Much of this will become clearer LATER!
The more we learn, the more all of this will come into focus!
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Introduction
 The globalization of the Internet has succeeded faster than anyone
could have imagined.
 The manner in which social, commercial, political and personal
interactions occur is rapidly changing to keep up with the evolution
of this global network.
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Network Centric World
Using Networks in our lives
6
Using Networks in our work
 Networks are no longer just a luxury, but a
necessity in conducting business for businesses,
governments, educational institutions, etc.
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Using Networks in our work
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Using Networks in
outside of work
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Networks – Behind the scenes
 More than just connecting cables… (that’s
the easy part)
 Today’s networks are complex and
sophisticated combination of protocols,
software, hardware, algorithms,
configurations, policies, and more
 Security
 Privacy
 24 x 7 availability and access
 Quality of Service
 Video on Demand
 Voice over IP (over the Internet)
 Redundancy and backup
 Mission critical applications
 Productivity and user expectations
 Wireless
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Networks Supporting the Way We Live
 The original idea about networks and the Internet was about sharing computer
resources – computer-to-computer communications.
 That quickly changed to people-to-people communications.
 Early networks were limited to character-based information.
 Communications between computers was not common nor easy to do.
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Networks Supporting the Way We Live
http://www.youtube.com/watch?v=
CQzUsTFqtW0
 Today’s networks carry between many different types of devices:
 Voice
 video streams
 Text
 graphics
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The Global Community
 Technology helps to create a world in which national borders, geographic
distances, and physical limitations become less relevant.
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Networks are integral in our daily lives
http://www.youtube.com/watch?
v=fQKNvPn3V8&mode=related&search=
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Examples of Today’s Popular Communication
Tools

Instant Messaging: AOL AIM and MSN Messanger
 Developed from earlier Internet Relay Chat (IRC)
 Incorporates features such as:
 file transfer
 voice
 video communication (web cam)
 chat
16
Weblogs (blogs)
 Weblogs (Blogs) are web pages that are easy to update and edit.
 Unlike commercial websites, which are created by professional
communications experts, blogs give anyone a means to communicate their
thoughts to a global audience without technical knowledge of web design.
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Wikis
 Wikis are web pages that groups of people can edit and view together.
 There is a public wiki, called Wikipedia, that is becoming a comprehensive
resource - an online encyclopedia - of publicly-contributed topics.
 Private organizations and individuals can also build their own wikis to capture
collected knowledge on a particular subject.
18
Podcasting
 Podcasting is an audio-based
medium that originally enabled
people to record audio and convert
it for use with iPods.
 Podcasting allows people to deliver
their recordings to a wide
audience.
 The audio file is placed on a
website (or blog or wiki) where
others can download it and play
the recording on their computers,
laptops, and iPods.
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Collaboration Tools
 Collaboration tools give people the opportunity to work together on shared
documents.
 Without the constraints of location or time zone, individuals connected to a
shared system can speak to each other, share text and graphics, and edit
documents together.
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Supporting Learning




E-Learning
On-line discussions and access to resources
On-line assignments and assessments
Blended distance learning
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Packet Tracer
Note: These screens
are not related.
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NetLab
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Online Courseware
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Networks Supporting the Way We Work
 Intranets, private networks in use by just one company, enable businesses
to communicate and perform transactions among global employee and
branch locations.
 Companies develop extranets, or extended internetworks, to provide
suppliers, vendors, and customers limited access to corporate data to check
order status, inventory, and parts lists.
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Networks Supporting the
Way We Play
 Email
 Personal Web Sites
 Sharing photos and videos
(YouTube)
 Travel: Expedia, Priceline,
Travelocity, etc.
 IM
 Gaming
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Communication
What is Communications?
 Different expectations depending on whether we are chatting via the Internet
or participating in a job interview.
 Before beginning to communicate with each other, we establish rules or
agreements to govern the conversation.
 These rules, or protocols, must be followed in order for the message to be
successfully delivered and understood.
 A protocol is nothing more than an agreement or rules to govern a way of
communicating.
 Among the protocols that govern successful human communication are:
 An identified sender and receiver
 Agreed upon method of communicating (face-to-face, telephone, letter,
photograph)
 Common language and grammar
 Speed and timing of delivery
 Confirmation or acknowledgement requirements
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Protocol
 Before beginning to communicate with each other, we establish rules or
agreements to govern the conversation.
 These rules, or protocols, must be followed in order for the message to be
successfully delivered and understood.
 A protocol is nothing more than an agreement or rules to govern a way of
communicating.
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Quality of
Communications
 Examples
 An identified sender
 An identified receiver
 Confirmation or acknowledgement requirements
 Format or order of information
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Quality of Communications
 Internal factors: nature of the message itself.
 The size of the message
 The importance of the message
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Network as a Platform
What is Networking?
Networking - the interconnection of
workstations, peripherals, terminals
and other devices.
Whatis.com: “In information
technology, networking is the
construction, design, and use of
network, including the physical
(cabling, hub, bridge, switch,
router, and so forth), the selection
and use of telecommunication
protocol and computer software for
using and managing the network,
and the establishment of operation
policies and procedures related to
the network.”
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Devices on a network
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Network Medium
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Network Applications and Protocols
 Some other applications:
 DNS, DHCP, HTTP, SMTP, FTP
 Some other protocols
 TCP/IP suite of protocols
 Ethernet
 Routing protocols
36
Converged Networks
 Traditional telephone, radio, television, and computer data networks each
have their own individual versions of the four basic network elements.
 Technology advances are enabling us to consolidate these disparate
networks onto one platform - a platform defined as a converged network.
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Converged Networks
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Architecture of the Internet
Network Architecture
 A fault tolerant
network is one that
limits the impact of a
hardware or software
failure and can recover
quickly when such a
failure occurs.
 A scalable network
can expand quickly to
support new users and
applications without
impacting the
performance of the
service being delivered
to existing users.
40
Quality of
Service
 Voice and live video transmissions require a level of consistent quality and
uninterrupted delivery that was not necessary for traditional computer
applications.
41
Security
 The security and privacy expectations that result from the use of
internetworks to exchange confidential and business critical information
exceed what the current architecture can deliver.
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Circuit Switched Connection-oriented Networks





Setup process
Temporary circuit
Failure in path, connection terminated
Limited number of circuits
Because resources at the various switching locations are dedicated to providing a finite
number of circuits, the quality and consistency of messages transmitted across a
connection-oriented network can be guaranteed.
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Packet Switched Connectionless Networks
 Single message can be broken into multiple message blocks (packets).
 Packets containing addressing information indicates both their origination point
and their final destination.
 Packets, can be sent through the network along various paths, and can be
reassembled into the original message upon reaching their destination.
(connectionless)
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Circuit Switched (connection oriented) vs
Packet Switched (connectionless)
Circuit Switched
 Dedicated circuit
 Guaranteed level of service
(bandwidth) - QoS
 Inefficient use of medium
 Single path, no redundancy
Packet Switched
 Shared circuit
 Messages divided into packets
 More efficient use of medium
 Redundancy, multiple possible
paths
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Scalable Network Architecture
 Tier-1 providers: ISPs provide national and international connections.
(Verizon, Sprint, AT&T, NTT, cable systems, etc.)
 Tier-2 providers: Provide regional service, pay Teir-1 for connectivity.
 Tier-3 providers: Provide service directly to end users, usually connected
through Tier-2 providers.
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Quality of Service
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Quality of Service
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QoS Matters
 Without properly designed and implemented QoS mechanisms, data packets
will be dropped without consideration of the application characteristics or
priority.
 Dropped distress call to an emergency response center, or of a lost control
signal to an automated piece of heavy machinery.
 A key responsibility for the network managers is to establish a QoS policy.
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Providing Network Security
 Securing a network infrastructure includes the physical securing of
devices that provide network connectivity and preventing unauthorized
access.
 Content security refers to protecting the information contained within the
packets being transmitted over the network and the information stored on
network attached devices.
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Trends in Networking
Trends
 Three major trends that are contributing to the future shape of
complex information networks:
 Increasing number of mobile users
 Proliferation of network capable devices
 Expanding range of services
52
Career Opportunities
 Information Technology and networking careers are growing and
evolving as fast as the underlying technologies and services.
 As networks increase in sophistication, the demand for people with
networking skills will continue to grow.
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IT is not the network, it is the users
 The IT (Information Technology)
department is not the network.
 The network is the users and their:
 Needs
 Expectations
 Requirements
 Uses
 It is not up to the IT department to
decide how the network gets used,
but how to meet the user
requirements and at the same time
provide the security and quality of
service necessary.
If IT doesn’t find a way, the
users will!
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A shift in attitude
 If an old school IT staff doesn’t change,
they will be replaced.
 There is too much at stake and there
are IT people who can meet the needs
of the users and the organization.
 Old school IT doesn’t work any more.
 We don’t support MACs.
 We can’t allow that application on
our network.
 We can’t give them access on our
network.
 We have too much to do already.
 We don’t support that.
 You don’t know about networks, so
we can’t do that.
 That would breach our security.
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Technical and Soft Skills
 Networking professionals need
more knowledge and skills today
than ever before.
 Tomorrow’s IT professionals will
need even more.
 Just as important, and sometimes
even more important are the soft
skills:
 Attitude
 Enthusiasm
 Communications skills
 Professionalism (conduct, etc.)
 A professional within the
organization.
56
Chapter 1
Living in a Network Centric
World
CIS 81 Networking Fundamentals
Rick Graziani
Cabrillo College
graziani@cabrillo.edu
Last Updated: 2/11/2008