N ETWORK S YSTEMS 3.01 U NDERSTAND THE PHYSICAL COMPONENTS OF A NETWORK.

NETWORK SYSTEMS

3.01 UNDERSTAND THE PHYSICAL COMPONENTS OF A NETWORK.

Network Technology

Network Devices

Types of Network Systems

Transmission Media

Linking to the Internet

NETWORK TECHNOLOGY

Understand Purpose of

Network

Identify Types of Systems

Identify Network Devices

GOALS

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

NETWORK DEVICE

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

ROUTER

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

SWITCH

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

WIRELESS ACCESS POINT

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

MODEM

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

END DEVICE

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

HOST (COMPUTER)

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.

NETWORK PRINTER

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

SERVER

Definition• The method of delivering video and voice

communications over a computer network

Advantages• Cheaper than the land lines

Disadvantages• Must have electrical current

VOIP PHONES

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 CAMERAS

Definition• A system in place for monitoring your home

and business environment.

SECURITY AND FIRE ALARMS

Network Systems• Systems that provide service to users across a

network

TYPES OF NETWORK SYSTEMS

Service Area• A network created around an individual’s

personal workspace

Example• The connection between a Smart phone and a

laptop

PERSONAL AREA NETWORK (PAN)

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.

LOCAL AREA NETWORK (LAN)

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

TRANSMISSION MEDIA

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

COAXIAL CABLE

Definition• Cable commonly used in high-speed wired

computer networksFeatures:

• 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)

TWISTED PAIR 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)

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.

FIBER OPTIC CABLE

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 standard100BaseT- Fast Ethernet1000BaseT- Gigabit Ethernet10GBaseT- 10GB Ethernet

ETHERNET STANDARDS

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

WIRELESS TRANSMISSION

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.

WI-FI

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 STANDARDS

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.

802.11 WIRELESS SECURITY

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.

CONNECTING TO THE INTERNET