Itn instructor ppt_chapter1 exploring the network smartskills

© 2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 1
Chapter 1:
Exploring the Network
Introduction to Networks

Presentation_ID 2© 2008 Cisco Systems, Inc. All rights reserved. Cisco Confidential
Chapter 1: Objectives
Students will be able to:
 Explain how multiple networks are used in everyday
life.
 Explain the topologies and devices used in a small to
medium-sized business network.
 Explain the basic characteristics of a network that
supports communication in a small to medium-sized
business.
 Explain trends in networking that will affect the use of
networks in small to medium-sized businesses.

Chapter 1
1.1 Globally Connected
1.2 LANs, WANs, and the Internet
1.3 The Network as a Platform
1.4 The Changing Network Environment
1.5 Summary and review Questions

Networking Today
Networks in Our Past and Daily Lives

Networking Today
The Global Community

Living in a Network-Centric World
Communication – An essential part of our lives
 How do you define communication?

 Establishing the Rules

Quality of Communications
For data networks, we use the same basic criteria to judge
success. As a message moves through the network, many
factors can prevent the message from reaching the recipient or
distort its intended meaning. These factors can be either
external or internal.
 External Factors
1. The quality of the pathway between the sender and the recipient
2. The number of times the message has to change form
3. The number of times the message has to be redirected or readressed
4. The number of other messages being transmitted simultaneously on the
communication network
5. The amount of time allotted for successful communication

Quality of Communications
Different types of messages may vary in complexity and
importance. Clear and concise messages are usually easier to
understand than complex messages. Important
communications require more care to ensure that they are
delivered and understood by the recipient.
 Internal Factors
1. The size of the message
2. The complexity of the message
3. The importance of the message
Large messages may be interrupted or delayed at different
points within the network. A message with a low importance or
priority could be dropped if the network becomes overloaded.

Interconnecting our Lives
Networking impacts in our daily lives
 Networks Support the Way We Learn

 Networks Support the Way We Communicate

 Networks Support the Way We Work

 Networks Support the Way We Play

Providing Resources in a Network
Networks of Many Sizes

Clients and Servers

Peer-to-Peer

LANs, WANs, and Internets
Components of a Network
There are three categories of network components:
 Devices
 Media
 Services

End Devices
Some examples of end devices are:
 Computers (work stations, laptops, file servers, web servers)
 Network printers
 VoIP phones
 TelePresence endpoint
 Security cameras
 Mobile handheld devices (such as smartphones, tablets,
PDAs, and wireless debit / credit card readers and barcode
scanners)

Network Infrastructure Devices
Examples of intermediary network devices are:
 Network Access Devices (switches, and wireless access
points)
 Internetworking Devices (routers)
 Security Devices (firewalls)

Network Media

Network Representations

Topology Diagrams

Internet Access Technologies

LANs and WANs
Types of Networks
The two most common types of network infrastructures are:
 Local Area Network (LAN)
 Wide Area Network (WAN).
Other types of networks include:
 Metropolitan Area Network (MAN)
 Wireless LAN (WLAN)
 Storage Area Network (SAN)

LANs and WANs
Local Area Networks (LAN)

LANs and WANs
Wide Area Networks (WAN)

The Internet

The Internet
Intranet and Extranet

The Internet
Intranet and Extranet
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.

Popular Communication Tools
The existence and broad adoption of the Internet has ushered
in new forms of communication that empower individuals to
create information that can be accessed by a global audience.
 Instant Messaging
 Weblogs (blogs)
 Wikis
 Podcasting
 Collaboration Tools

Connecting to the Internet
Connecting Remote Users to the Internet

Connecting to the Internet
Connecting Businesses to the Internet

Converged Networks
The Converging Network

Converged Networks
Planning for the Future

Reliable Network
Supporting Network Architecture
As networks evolve, we are discovering that there are four
basic characteristics that the underlying architectures need to
address in order to meet user expectations:
 Fault Tolerance
 Scalability
 Quality of Service (QoS)
 Security

Reliable Network
Fault Tolerance
 The expectation that the Internet is always available to the
millions of users who rely on it requires a network
architecture that is designed and built to be fault tolerant. 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.

Reliable Network
Fault Tolerance in Circuit Switched Network

Reliable Network
Packet-Switched Networks

Reliable Network
Scalability
 A scalable network can expand quickly to support new users
and applications without impacting the performance of the
service being delivered to existing users. The ability of the
network to support these new interconnections depends on a
hierarchical layered design for the underlying physical
infrastructure and logical architecture.

Reliable Network
Scalable Networks – Tier 1

Reliable Network

Reliable Network
Scalable Networks – Hierarchical

Reliable Network
Scalable Networks – Distributed

Reliable Network
Scalable Networks - Peers

Reliable Network
Providing (QoS)

Reliable Network
Providing (QoS)
Examples of priority decisions for an organization might
include:
 Time-sensitive communication - increase priority for services
like telephony or video distribution.
 Non time-sensitive communication - decrease priority for web
page retrieval or email.
 High importance to organization - increase priority for
production control or business transaction data.
 Undesirable communication - decrease priority or block
unwanted activity, like peer-to-peer file sharing or live
entertainment

Reliable Network
Providing (QoS)

Reliable Network
Providing Network Security

Reliable Network
Security measures taken in a network should:
 Prevent unauthorized disclosure or theft of information
 Prevent unauthorized modification of information
 Prevent Denial of Service
Means to achieve these goals include:
 Ensuring confidentiality
 Maintaining communication integrity
 Ensuring availability

Reliable Network
 Ensuring Confidentiality
Data privacy is maintained by allowing only the intended and authorized
recipients - individuals, processes, or devices - to read the data.
Having a strong system for user authentication, enforcing passwords
that are difficult to guess, and requiring users to change them
frequently helps restrict access to communications and to data stored
on network attached devices. Where appropriate, encrypting content
ensures confidentiality and minimizes unauthorized disclosure or theft
of information.

Reliable Network
 Maintaining Communication Integrity
Data integrity means having the assurance that the information has not
been altered in transmission, from origin to destination. Data integrity
can be compromised when information has been corrupted - willfully or
accidentally - before the intended recipient receives it.
Source integrity is the assurance that the identity of the sender has
been validated. Source integrity is compromised when a user or device
fakes its identity and supplies incorrect information to a recipient.
The use of digital signatures, hashing algorithms and check sum
mechanisms are ways to provide source and data integrity across a
network to prevent unauthorized modification of information.

Reliable Network
 Ensuring Availability
Ensuring confidentiality and integrity are irrelevant if network resources
become over burdened, or not available at all. Availability means
having the assurance of timely and reliable access to data services for
authorized users.
Resources can be unavailable during a Denial of Service (DoS) attack
or due to the spread of a computer virus. Network firewall devices,
along with desktop and server anti-virus software can ensure system
reliability and the robustness to detect, repel, and cope with such
attacks.
Building fully redundant network infrastructures, with few single points of
failure, can reduce the impact of these threats.

Reliable Network

Network Trends
New trends
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.
Traditional IT positions like programmers, software engineers,
data base administrators and network technicians are now joined
by new titles, such as network architect, e-Commerce site
designer, information security officer, and home integration
specialist.
As students of networking technology, we examine the
components of data networks and the roles they play in enabling
communication. This course,is designed to empower you with the
networking knowledge to build and manage these evolving
networks.

Network Trends
New trends

Network Trends
New trends
Some of the top trends include:
 Bring Your Own Device (BYOD)
 Online collaboration
 Video
 Cloud computing

Network Trends
Bring Your Own Device (BYOD)

Network Trends
Online Collaboration

Network Trends
Video Communication

Network Trends
Cloud Computing
There are four primary types of clouds:
 Public clouds
 Private clouds
 Custom clouds
 Hybrid clouds

Network Trends
Data Centers
A data center is a facility used to house computer systems and
associated components including:
 Redundant data communications connections
 High-speed virtual servers (sometimes referred to as server
farms or server clusters)
 Redundant storage systems (typically uses SAN technology)
 Redundant or backup power supplies
 Environmental controls (e.g., air conditioning, fire
suppression)
 Security devices

Networking Technologies for the Home
Technology Trends in the Home

Powerline Networking

Wireless Broadband

Future of Networking
Network Security

Network Security
Security Threats
The most common external threats to networks include:
 Viruses, worms, and Trojan horses
 Spyware and adware
 Zero-day attacks, also called zero-hour attacks
 Hacker attacks
 Denial of service attacks
 Data interception and theft
 Identity theft

Network Security
Security Solutions
Network security components often include:
 Antivirus and antispyware
 Firewall filtering
 Dedicated firewall systems
 Access control lists (ACL)
 Intrusion prevention systems (IPS)
 Virtual Private Networks (VPNs)

Network Architectures
Cisco Network Architectures

Network Architectures
Cisco Certified Network Associate (CCNA)

Exploring the Networking
Summary
In this chapter, you learned:
 Networks and the Internet have changed the way we
communicate, learn, work, and even play.
 Networks come in all sizes. They can range from simple
networks consisting of two computers, to networks
connecting millions of devices.
 The Internet is the largest network in existence. In fact, the
term Internet means a ‘network of networks. The Internet
provides the services that enable us to connect and
communicate with our families, friends, work, and interests.

Summary
 The network infrastructure is the platform that supports the
network. It provides the stable and reliable channel over
which communication can occur. It is made up of network
components including end devices, intermediate device, and
network media.
 Networks must be reliable.
 Network security is an integral part of computer networking,
regardless of whether the network is limited to a home
environment with a single connection to the Internet, or as
large as a corporation with thousands of users.

Summary
 The network infrastructure can vary greatly in terms of size,
number of users, and number and types of services that are
supported on it. The network infrastructure must grow and
adjust to support the way the network is used. The routing
and switching platform is the foundation of any network
infrastructure.

Summary
Review
 Describe the external factors that impact network
communication.
External factors affecting the quality of communication are related to the
processes that devices use to talk to each other and include:
• Whether a confirmation of the message was returned to the sender.
• The quality of the pathway between the sender and the recipient.
• The number of times the message has to change form.
• The number of other messages in the communication network.
• The number of times the message is reformatted.
• The amount of time allotted for successful communication.

Summary
Review
 Describe the Internal factors that impact network
communication.
Internal factors that interfere with communication are related to the
nature of the communication itself. The communication may vary in
complexity and importance. Clear and concise messages are usually
easier to understand than complex messages. Important
communications require more care to ensure that the meaning is
received properly.
Internal factors affecting the quality of communication include:
• The size of the message
• The complexity of the message
• The importance of the message

Summary
Review
 Describe network-supported technologies that impact how
people learn, work, and play.
Includes instant messaging, weblogs, podcasting, collaboration tools
using text, graphic, audio and video technologies over both fixed and
mobile data networks.

Summary
Review
 What is data? What is a data network? What is a converged
network?
Data is the pieces of information, such as files, audio, phone calls and
video shared across the network.
A data network consists of:
• Devices that communicate with each other
• A means of connecting these devices together – a medium that can
transport messages from one device to another
• The digital messages or units of information that will travel from one
device to another
• Rules of agreements to govern how the messages are sent, directed,
and received.

Summary
Review
 What is a converged network?
Traditionally telephone, data communications between computers,
radio, and television each had separate networks and each required a
different technology to carry its particular communication signal.
Additionally, each service had its own set of rules and standards to
ensure the successful communication of its service across a specific
medium.
Technology can now consolidate these disparate networks into one
platform – a platform we define as the converged network. The flow of
voice, radio, video, and data travelling over the same network
eliminates the need to create and maintain separate networks. As
converged networks become more common, businesses and individual
users can use a single network for its services.

Summary
Review
 Why does Quality of Service matter on a data network?
Converged networks carry multiple types of communication. Data
network resources, however are always constrained by budgets,
physical limitations, and technology. The existence of these limitations
means that decisions must be made regarding the priority of different
types of communication.
The management of different types of communication involves
balancing both the traffic´s importance and its characteristics. Both of
these factors are considered when developing a Quality of Service
(QoS) strategy for managing data in a given data network.

Summary
Review
 What happens without a properly designed and implemented
QoS mechanism?
Without properly designed and implemented QoS mechanisms, data
packets will be dropped without consideration of the application
characteristics or priority.

Summary
Review
 What does security mean in the context of data networks?
Data network security has two aspects:
• Interception of data communications – data encryption can negate
such interceptions.
• Unauthorized access to the network and its data – User
authentication (usernames, passwords and classifications are tools
to prevent this - In addition to physical security)
Intruders may desire to gain access to information for monetary gain.
They steal financial records or sell trade secrets to competitors. For
others stealing data is merely a game about which they can brag, often
boast about it their latest online conquests. Many have limited computer
and network skills and do this just for fun. Some change, destroy or just
disrupt. Some are disgruntled employees to wreak havoc.

Lab: Skills Integration Challenge: Introduction to PT

Lab: Skills Integration: Use of TCP/IP in PT demo

Itn instructor ppt_chapter1 exploring the network smartskills

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