Transcript What is a Network?

NETWORKING
FUNDAMENTALS
JAY ANTHONY R. NUÑEZ
OBJECTIVES
ICT
Upon completion of the FINAL TERM, the students
should be able to:
 define a network, different kinds of network and devices, and
the components of a network and their functions.
 create and assemble straight-through and cross-over cables.
 define Internet and its differences to the other kinds of
network.
 build a Peer-to-Peer Cable Network.
OBJECTIVES (cont.)
ICT
Upon completion of the FINAL TERM, the students
should be able to:
 demonstrate sharing of information or data through the use of
network.
 list procedures to install and troubleshoot network interface
cards (NICs) and modems.
 explain the functions of network and Information and
Communications Technology in a safe, secure and efficient
marine navigation.
CONTENT
ICT
 Introduction to Networks
 Types of Network
 Network Architecture and Devices
 Network Cabling and Topology
 Internet and the World Wide Web
 Network Installation and Troubleshooting
What is a Network?
A combination of computer hardware, cabling,
network devices, and computer software
used together to allow computers
to communicate with each other.
A network consists of 2 or more computers
connected together, and they can
communicate and share resources.
(e.g. hardware, software, information)
The Goal of a Network
To allow multiple computers to communicate.
Communication might be:
• a download of an MP3 audio file for your MP3 player
• checking the latest sports scores
• using an instant-messaging service, such as Viber
• sending text messages to a friend
• writing an e-mail and sending it to a business associate.
• chatting on facebook or skype
Benefits of a Network
 Information sharing: Authorized users can use other computers on
the network to access and share information or data. This could include
special group projects, databases, etc.
 Hardware sharing: One device connected to a network, such as a
printer or scanner, can be shared by many users.
Benefits of a Network (cont.)
 Software sharing: Instead of purchasing and installing a software
program on each computer, it can be installed on the server. All of the users
can then access the program from a single location.
 Collaborative environment: Users can work together on group
projects by combining the power and capabilities of diverse equipment.
centralized administration and support
A Simple Network
A printer shared by 4 personal computers.
Risks of Network Computing
The security of a computer network is challenged
everyday by:
• Equipment malfunctions
• System failures
•Note: equipment malfunctions and system failures may be
caused by natural disasters such as floods, storms, or fires, and
electrical disturbances
• Computer hackers
• Virus attacks
Network Architecture
 Refers to the logical and structural layout or the
complete framework of an organization's computer
network
 Consisting of the hardware, software, connectivity,
communication protocols and mode of transmission,
such as wired or wireless
 Provides the detail overview of a network
Few terms related to Network
 Workstation or Nodes
Refers to a computer that are
attached to a network.
 Server
- The master computer
- Facilitates the sharing of
data, software and
hardware concepts.
Components of a Network
Peripherals
Shared peripheral devices do not communicate
directly on the network. Instead, peripherals rely on
their connected host to perform all network
operations.
Examples :
cameras, scanners, and locally attached printers
Components of a Network
Hosts
Hosts send and receive user traffic. A host is a
generic name for most end-user devices. A host has an IP
network address.
Examples:
personal computers and network attached printers
Components of a Network
Network Devices
Networking devices connect other devices, mainly
hosts. These devices move and control network traffic.
Examples:
hubs, switches, and routers.
Components of a Network
Network Media
Network media provides connections between hosts
and network devices.
Network media can be wired, such as copper and fiber
optic or use wireless technologies.
Network Hardware and Software
Switch
small hardware device
that joins multiple
computers together
within one local area
network (LAN).
Network Hardware and Software
RJ-45 Connector
Register Jack 45 is an 8
wire connector which is
commonly used to
connect computers on
LAN
Network Hardware and Software
Hub
connects computers
together in a star
topology network.
Network Hardware and Software
Repeater
an electronic device that
receives a signal and
retransmits it at a higher
level and/or higher power,
or onto the other side of
an obstruction, so that the
signal can cover longer
distances without
degradation.
Network Hardware and Software
Modem
(MOdulator-DEModulator)
an electronic device that
makes possible the
transmission of data to or
from a computer via
telephone or other
communication lines.
Network Hardware and Software
NIC
(Network Interface Card)
is a computer hardware
component designed to
allow computers to
communicate over a
computer network.
Network Hardware and Software
Media converters
simple networking
devices that make it
possible to connect
two dissimilar media
types such as twisted
pair with fiber optic
cabling.
Network Hardware and Software
Wireless Access Point
a device that allows
wireless
communication
devices to connect to a
wireless network using
Wi-Fi, Bluetooth or
related standards.
Network Hardware and Software
Firewall
a part of a computer
system or network
that is designed to
block unauthorized
access while
permitting outward
communication.
Kinds of Networks
Depending on one’s perspective, we can classify
networks in different ways.
• Based on transmission media: Wired (UTP, coaxial
cables, fiber-optic cables) and Wireless
• Based on network size: LAN and WAN
• Based on management method: Peer-to-peer and
Client/Server
• Based on topology (connectivity): Bus, Star, Ring
Kinds of Networks (Trans Media)
 Two main categories:
Guided ― wires, cables
 Unguided ― wireless transmission, e.g. radio,
microwave, infrared, sound

 We will concentrate on guided media here:
Twisted-Pair cables:
 Unshielded Twisted-Pair (UTP) cables
 Shielded Twisted-Pair (STP) cables
 Coaxial cables
 Fiber-optic cables

Twisted Pair Cables
 If the pair of wires are not twisted, electromagnetic
noises from, e.g., motors, will affect the closer wire
more than the further one, thereby causing errors
Unshielded Twisted Pair(UTP)
 Typically wrapped inside a plastic cover (for mechanical
protection)
 A sample UTP cable with 5 unshielded twisted pairs of
wires.
Insulato
r
Metal
Categories of UTP Cables
EIA classifies UTP cables according to the quality:
 Category 1 ― the lowest quality, only good for voice, mainly
found in very old buildings, not recommended now
 Category 2 ― good for voice and low data rates (up to 4Mbps
for low-speed token ring networks)
 Category 3 ― at least 3 twists per foot, for up to 10 Mbps
(common in phone networks in residential buildings)
 Category 4 ― up to 16 Mbps (mainly for token rings)
 Category 5 (or 5e) ― up to 100 Mbps (common for networks
targeted for high-speed data communications)
 Category 6 ― more twists than Cat 5, up to 1 Gbps
Chapter 2: NETWORK CABLING
31
UTP CABLE GRADES
Category
Frequency
Primary Application
1
Up to 0 MHz
Voice networks
2
Up to 1 MHz
Voice and low-speed data
networks less than 4
Mbps
3
Up to 16 MHz
Voice and data networks
from 4 to 100 Mbps
4
Up to 20 MHz
16-Mbps Token Ring
5
Up to 100 MHz
100-Mbps Fast Ethernet
5e
Up to 100 MHz
1000-Mbps Gigabit
Ethernet
6
Up to 250 MHz
1000-Mbps Gigabit
Ethernet
STRAIGHT THROUGH AND CROSSOVER WIRING
 Wiring within a twisted pair cable is configured as either

Straight through, where each wire (or pin) is attached to the
same contact point at each end.

Crossover, where transmit contacts on each end of the cable
are connected to the receive contact at the other end
Coaxial Cables
 In general, coaxial cables, or coax, carry signals of higher freq
(100KHz–500MHz) than UTP cables.
 Outer metallic wrapping serves both as a shield against noise
and as the second conductor that completes the circuit
 the primary type of cabling used by the cable television industry.
Fiber Optic Cables
Advantages and Disadvantages
 Noise resistance ― external light is blocked by outer jacket
 Less signal attenuation ― a signal can run for miles without
regeneration (currently, the lowest measured loss is about ~4%
or 0.16dB per km)
 Higher bandwidth ― currently, limits on data rates come from
the signal generation/reception technology, not the fiber itself
 Cost ― Optical fibers are expensive
 Installation/maintenance ― any crack in the core will degrade
the signal, and all connections must be perfectly aligned
Kinds of Networks - LAN (SIZE)
Local Area Network (LAN) – a network that spans a small
area such as a building or an office.

Software applications and other resources are stored on a file
server.

Print servers enable multiple users to share the same printer.
Examples:
•
•
Network inside the Computer Lab
Network in your home
Kinds of Networks (Management)
 Peer to peer
Computers connect with each other in a workgroup to
share files, printers, and Internet access. This is used
to connect a small number of computers.
 Client/Server
sends information from a client computer to a server,
which then relays the information back to the client
computer, or to other computers on the network
Kinds of Networks - WAN (SIZE)
Wide Area Network (WAN) –
 A network that uses long-range telecommunication links
to connect 2 or more LANs/computers housed in different
places far apart.
 a network that spans a wide geographical area

Towns, states, countries
Examples:
• Network of Ce-C Panglao and Tagbilaran Campus
• Internet
• Broadband Cable Network
TYPES OF NETWORK TOPOLOGIES

There are three main local area network (LAN)
topologies:




Bus
Star
Ring
Other network topologies include:


Mesh
Wireless
BUS TOPOLOGY






The bus topology supports thick and thin coaxial segments.
Segments are connected by repeaters.
The bus topology uses the baseband signaling method.
Signals are broadcast in both directions simultaneously.
Both ends of each segment require termination to avoid
reflection.
End systems connect to the segment in a linear manner.
THICK AND THIN COAXIAL BUS
STAR TOPOLOGY


The star topology can use coaxial, twisted pair, or
fiber optic cable.
A central device (hub) connects hubs and nodes to
the network.


Each node connects to its own dedicated port on the hub.
Hubs broadcast transmitted signals to all connected
devices.
A SIMPLE STAR TOPOLOGY
RING TOPOLOGY


The ring topology can use twisted pair or fiber optic
cabling.
A central device (hub) connects hubs and nodes to
the network.


Each node connects to its own dedicated port on the hub.
You can connect multiple hubs to form a larger ring.
A RING NETWORK
44
MESH TOPOLOGY


Typically uses fiber optic cabling for redundant wide
area network (WAN) links
Requires an enormous amount of cable
WIRELESS TOPOLOGY


Cell-based technology that uses unbounded media
Two wireless topologies:
Ad hoc WLAN (Wireless LAN)



WiFi (Wireless Fidelity)
Infrastructure
AD HOC WLAN
INFRASTRUCTURE WLAN
We have seen how networks
are established, but how does
data travels in a network?
Assessment:
Patch Cable Construction
STRAIGHT-THROUGH AND
CROSS-OVER PATCH CABLE
Objectives
 Construct a patch cable following the 568A and
568B standards
 Explain the difference between the 568A and
568B standards
 Test a patch cables
Objectives
 Construct a patch cable following the 568A and
568B standards
 Explain the difference between the 568A and
568B standards
 Test a patch cables
Patch Cable Types
 Straight – through cable uses:
router to a hub
 computer to a switch
 LAN port to a switch, hub, or computer

 Crossover Cable uses:
 computer to a router
 computer to a computer
 router to a router
 switch to a switch
 hub to a hub
Patch Cable Pin Assignments
568B
568A
Pin #
Color
Pin # Color
1
Green/white
1
Orange/white
2
Green
2
Orange
3
Orange/white
3
Green/white
4
Blue
4
Blue
5
Blue/white
5
Blue/white
6
Orange
6
Green
7
Brown/white
7
Brown/white
8
Brown
8
Brown
Cable Connection
STRAIGHT-THROUGH
CROSSOVER
568B
568A
568B
568B
STRAIGHT-THROUGH DIAGRAM
568A
568A
CROSSOVER DIAGRAM
568A
568B
CABLE USAGE ON DIFFERENT DEVICES
Activity
Create a straight –through and
crossover cable.