N ETWORK S YSTEMS
3.01 U NDERSTAND THE PHYSICAL COMPONENTS
OF A NETW ORK .
OBJECTIVE
Understand the Network Systems
Pathway
Students will understand key terms that
make up physical components of a
network.
FAMILIAR TERMS
NETWORK TECHNOLOGY
Network
Devices
Types of
Network
Systems
Network
Technology
Transmission
Media
Linking to the
Internet
GOALS
Identify
Network
Devices
Identify
Types of
Systems
Understand
Purpose of
Network
A COMPUTER NETWORK
NETWORKING ACTIVITYVOCABULARY
Discuss what you already know about
the term.
Use the YELLOW paper to note your
answers.
1) Write down what you already know.
2) Define term using Internet
3) Provide an example of the
vocabulary
NETWORK DEVICE
Definition:
• A device is a component used to connect
computers or other electronic devices
together so they can share files or resources.
Use:
• Performs tasks like
routing and communicating
Types of Devices:
• Router, Switch,
• Modem, Access Point
ROUTER
Definition
• A hardware device or software program that
manages the paths along which information travels
within and between networks
• A router uses the IP address to determine the
pathway.
Advantages
• Intelligent software that enables it to pass data
quickly across the network
Disadvantages
• Requires configuration
• Required for SOHO configurations
SWITCH
Definition
• A device that links multiple computers,
telephones, cameras, alarms, or networks on
the same data connection
• Provides individual connections for each
host within the local network.
• The switch uses the MAC address to determine
the pathway.
• MAC stands for Media Access Control
• The MAC address is the hardware address
of the NIC (Network Interface Card) on the
end device.
• It is unique for every device.
SWITCH
Advantages
• Break-up collision domains (fewer collisions)
• Faster transfer rate than hub
• Improves the throughput of Ethernet networks
Disadvantages
• Does not create IP addresses
• No intelligent software
WIRELESS ACCESS POINT
Definition
• Joins wireless clients to a wired Ethernet
network
• Also known as “hot spots”
Advantages
• Mobility
• Network flexibility
Disadvantages
• Security vulnerability
• Signal interference and limited number of
frequencies
• Placement
MODEM
Definition
• Performs the functions of a modulator and a
demodulator
• Used with a dial-up Internet connection.
Modulator
• Enables computers to interpret data received
from a network
Demodulator
• Allows a modem to send
information formatted to be
read by network computers
END DEVICE
Definition:
A device that is either the source or the destination
of a packet on a network.
Every device must have an IP address, MAC
address and Network Interface Card.
Examples:
Computer, Printer, Server, VOIP phones, cameras
and alarms
HOST (COMPUTER)
Definition
• A computing device on a computer network
Responsibilities / Tasks / Role / Functions
• Manages tasks, communicates instructions, or
delivers specific services to other computers, or
clients, on a network
• It is the destination of a message sent through a
network.
• It includes computers, mobile phones, scanners
and printers.
Also known as…
• Computer
• Terminal
• Node
NETWORK PRINTER
Definition
• A printer that allows for multiple users to print
from remote locations of the network
• It contains its own network interface card, and
requires its own IP and MAC address.
SERVER
Definition
• A computer with the software capabilities that
provides services to other computer programs
and their users.
Types
• File Server
• DHCP & DNS
• Database
• Web
• Print
• Gaming
• Email
• Music
VOIP PHONES
Definition
• The method of delivering video and voice
communications over a computer network
Advantages
• Cheaper than the land lines
Disadvantages
• Must have electrical current
SECURITY CAMERAS
Definition
• A digital camera connected to a computer
network that allows the user to record video.
Commonly used for surveillance.
Advantages
• Powered with Ethernet cable
• Small, portable and easily accessibility
• Models can be wireless
Disadvantages
• High network bandwidth
• Requires lots of digital storage space
SECURITY AND FIRE ALARMS
Definition
• A system in place for monitoring your home
and business environment.
TYPES OF NETWORK SYSTEMS
Network Systems
• Systems that provide service to users across a
network
PERSONAL AREA NETWORK (PAN)
Service Area
• A network created around an individual’s
personal workspace
Example
• The connection between a Smart phone and a
laptop
LOCAL AREA NETWORK (LAN)
Service Area
• A network created for a home or other small
geographic area
Types
• Physical
• Wireless
Example
• A network in a school or classroom
LOCAL AREA NETWORK (LAN)
More facts
• Consists of high speed network infrastructure at
a single location used to deliver network
applications and services
• Ethernet is widely used in a LAN network.
• It has a lower cost than other transmission
media.
• It is easier to use than other transmission
media.
• It has the capability to scale up to and past
multi-gigabit speeds.
TRANSMISSION MEDIA
Definition
• Provides a path for information to be sent
from one computer to another through a
network
Types of Transmission Media:
• Coaxial cable
• Ethernet cable
• Fiber optic cable
• Wireless transmission
COAXIAL CABLE
Definition
• Cable specifically designed for carrying
an electronic signal
• Two variations- ThinNet and ThickNet
Features:
• Max Cable Length is 200 meters (ThinNet) or
500 meters (ThickNet)
• Cost (Twisted Pair < Coaxial < Fiber Optic)
• Ease of Installation (Moderately difficult to install)
• Susceptible to EMI and RFI interference
• Consists of four layers of material to reduce
interference
TWISTED PAIR CABLE
Definition
• Cable commonly used in high-speed wired
computer networks
Features:
• Cable Length (Up to 100 meters)
• Cost (Twisted pair is the cheapest)
• Ease of Installation (Easy to install)
• Susceptible to EMI and RFI interference
• Twisted pair wiring reduces interference
• Types
• Straight-through
• Crossover
• Rollover (console cable)
UNSHIELDED TWISTED PAIR (UTP)
• Found in Ethernet and phone systems
• Most common type of cable used for computer
networks.
• Used for short to medium distances (up to 100
meters)
• Not shielded against EMI or other
interference
SHIELDED TWISTED PAIR (STP)
• Found in Ethernet and phone systems
• Shielded to protect against EMI
• More costly than UTP
• Used for short to medium distances (up to 100M)
FIBER OPTIC CABLE
Definition
• Cable made of super-thin filaments of glass or
other transparent materials that can carry beams
of light
Features:
• Cable Length (Longest transmission, use of light)
• Cost (Fiber Optic is most expensive)
• Ease of Installation (Difficult to install)
FIBER OPTIC CABLE
More Features:
• Less susceptible to interference
• Data can be sent at the speed of light.
• A LASER transmitter encodes frequency signals
into pulses of light: ones and zeros are sent
through the cable.
• The receiving end of the transmission translates
the light signals back into data which can be
read by a computer.
ETHERNET STANDARDS
 The Institute of Electrical and Electronics Engineers
(IEEE) defines wired transmission in the 802.3 standard.
 Typically written as XBaseT (X= transmission speed) T=
Twisted pair cable.
 Note: The first two standards listed do not use twisted pair
cabling.






10Base2- Thin Coaxial cable ( ThinNet)
10Base5- Thick Coaxial cable ( ThickNet)
10BaseT- Original twisted pair standard
100BaseT- Fast Ethernet
1000BaseT- Gigabit Ethernet
10GBaseT- 10GB Ethernet
WIRELESS TRANSMISSION
Definition
• Able to connect computers to other computers and printers
the same way a wired network is, but without wires.
Features:
• Range (Depends on factors such as wireless card, access
point, and obstacles in between)
• Cost (Wireless price is dependent upon the complexity of
the setup.)
• Ease of Installation (Easy)
• 802.11 (a,b,g,n)
• Interference can be caused by cordless telephones and
microwaves
• Wireless security includes: WEP, WPA, and WPA2
WI-FI
 Wireless Fidelity
• The original standards for wireless networks
were put out by IEEE in 1990. These standards
are also called Wi-Fi, or Wireless Fidelity.
 SSID
• The service set identifier, or SSID, is a name
that identifies a particular Wi-Fi network to a
wireless device.
• The SSID is required, can be up to 32
characters long and is case-sensitive.
802.11 WIRELESS STANDARDS
Designation
Ratification Date
Wireless Band
Data Rate
802.11
1997
2.4 GHz
2 Mbps
802.11a
1999
5 GHz
54 Mbps
802.11b
1999
2.4 GHz
11 Mbps
802.11g
2002
2.4 GHz
54 Mbps
802.11n
2009
2.4 GHz and 5 GHz 54 Mbps to 600 Mpbs
802.11 WIRELESS SECURITY
 WEP
• WEP or Wired Equivalent Privacy uses a 64 or
128 bit key.
• WEP keys are vey insecure.
• Various attacks allow users to gain unauthorized
access to the network.
802.11 WIRELESS SECURITY
 WPA
• Wi-Fi Protected Access was designed to improve
upon WEP’s features.
• Two improvements over WEP are:
• Improved data encryption the temporal key
integrity protocol (TKIP).
• User authentication which allows only
authorized network users access.
802.11 WIRELESS SECURITY
 WPA2
• WPA2 added a new Advanced Encryption
Standard (AES) mode with mathematically
proven security.
• WPA2 offers a Pre-shared key (PSK) mode for
SOHO use.
• The PSK may be entered as a string of 64
hexadecimal digits or a passphrase.
• Shared-key WPA remains vulnerable to
password cracking attacks if users rely on a
weak passphrase.
CONNECTING TO THE INTERNET
 Internet Service Provider
• In order to access the Internet and the World
Wide Web you will need an Internet Service
Provider (ISP)
• The ISP is a company that has a permanent
connection to the Internet.
• A computer requires an ISP in order for
communication software to work
• Once again every device will need a MAC
address, IP address and Network Interface
Card.