Chapter 1:
Exploring the Network
Introduction to Networks
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Networking Today
Networks in Our Past and Daily Lives
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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
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Providing Resources in a Network
Clients and Servers
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Providing Resources in a Network
Peer-to-Peer
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LANs, WANs, and Internets
Components of a Network
There are three categories of network components:
1. Devices
2. Media
3. Services
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Components of a Network
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)
End devices are referred to as hosts.
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Components of a Network
Network Infrastructure (Intermediary) Devices
Examples of intermediary network devices are:
Network Access Devices (switches, and wireless access
points)
Internetworking Devices (routers)
Security Devices (firewalls)
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Components of a Network
Network Media
Different types of network
media have different
features and benefits.
• The distance the media
can successfully carry a
signal.
• The environment in
which the media is to be
installed.
• The amount of data and
the speed at which it
must be transmitted.
• The cost of the media
and installation
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Components of a Network
Network Representations
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Components of a Network
Topology Diagrams
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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)
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LANs and WANs
Local Area Networks (LAN)
•
An individual network usually spans a single
geographical area, providing services and applications
to people within a common organizational structure,
such as a single business, campus or region.
A LAN is usually administered by a single organization.
•
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LANs and WANs
Wide Area Networks (WAN)
When a company or organization has locations that are separated by large
geographical distances, it may be necessary to use a telecommunications
service provider (TSP) to interconnect the LANs at the different locations.
These networks that connect LANs in geographically separated locations are referred to
as Wide Area Networks (WANs).
WANs use specifically designed network devices to make the interconnections between
LANs.
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LANs, WANs, and Internets
The Internet
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LANs, WANs, and Internets
Internet Access Technologies
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Connecting to the Internet
Connecting Remote Users to the Internet
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Connecting to the Internet
Connecting Businesses to the Internet
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Converged Networks
Multiple services-multiple networks
Traditional telephone, radio, television, and
computer data networks each have their own
individual networks, every one of these services
required a different technology to carry its
particular communication signal.
Converged networks
Technology advances are enabling us to
consolidate these disparate networks onto one
platform - a platform defined as a converged
network.
The flow of voice, video, and data traveling
over the same network eliminates the need to
create and maintain separate networks.
On a converged network there are still many
points of contact and many specialized
devices - for example, personal computers,
phones, TVs, personal assistants, and retail
point-of-sale registers - but only one common
network infrastructure.
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Converged Networks
Planning for the Future
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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:
1. Fault Tolerance
2. Scalability
3. Quality of Service (QoS)
4. Security
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Reliable Network
Fault Tolerance: Circuit Switched Network
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Reliable Network
Fault Tolerance: Packet-Switched Networks
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Reliable Network
Scalable Networks
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Reliable Network
Providing (QoS)
Networks must provide secure, predictable, measurable, and, at
times, guaranteed services.
The packet-switched network architecture does not guarantee
that all packets that comprise a message will arrive on time, in
their correct in order, or even that they will arrive at all.
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
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Reliable Network
Providing Network Security
There are two types of network security concerns:
1. Securing a network infrastructure: includes the physical securing of
devices that provide network connectivity and preventing
unauthorized access to them.
2. 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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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
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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)
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Network Trends
New trends
Some of the top trends include:
Bring Your Own Device (BYOD)
Online collaboration
Video
Cloud computing
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Network Trends
Bring Your Own Device (BYOD)
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Network Trends
Online Collaboration
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Network Trends
Video Communication
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Network Trends
Cloud Computing
There are four primary types of clouds:
Public clouds
Private clouds
Custom clouds
Hybrid clouds
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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
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Networking Technologies for the Home
Technology Trends in the Home
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Networking Technologies for the Home
Powerline Networking
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Networking Technologies for the Home
Wireless Broadband
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