COMPUTER EDUCATION 9 MODULE 4 Network Connectivity Prepared By: Engr. Jeremy M. Flores
Aug 19, 2015
COMPUTER EDUCATION 9
MODULE 4Network Connectivity
Prepared By: Engr. Jeremy M. Flores
COMMUNICATION
We live in a truly connected society. We can
communicate almost instantaneously with
others worldwide.
COMMUNICATION
As the power and flexibility of our communication systems
have expanded, the sophistication of the networks
that support these systems has become increasingly
critical and complex.
COMMUNICATION
Computer communication is the process of sharing
data, programs, and information between two
or more computers.
COMMUNICATION
Electronic MailTexting and Messaging
Internet TelephoneElectronic Commerce
CONNECTIVITY
Connectivity is a concept related to using computer
networks to link people and resources.
THE WIRELESS REVOLUTION
The single most dramatic change in connectivity and communications in
the past few years.
THE WIRELESS REVOLUTION
It refers to the widespread use of mobile devices like smartphones and tablets
with wireless Internet connectivity.
THE WIRELESS REVOLUTION
So, what’s the revolution?
Today’s mobile computers support E-mail, Web
access, and variety of Internet applications.
THE WIRELESS REVOLUTION
Most experts say that the Wireless Revolution is just
in its beginning phase.
COMMUNICATION SYSTEMS
It is an electronic systems that transmit data from one location to another,
whether wired or wireless.
COMMUNICATION SYSTEMS
Four Basic Elements
Sending / Receiving DevicesConnecting DevicesData Transmission
SpecificationCommunication Channel
COMMUNICATION SYSTEMS
COMMUNICATION SYSTEMS
Sending / Receiving Devices
These are often a computer or specialized communication devices that originate and
accept messages in the form of data, information, and/or
instructions.
COMMUNICATION SYSTEMS
Connecting Devices
These devices act as an interface between the sending and receiving
devices and communication channel.
COMMUNICATION SYSTEMS
Connecting Devices
They convert outgoing messages into packets that can
travel across the communication channel and
reverse the process for incoming messages.
COMMUNICATION SYSTEMS
Data Transmission Specification
These are rules and procedures that coordinate the sending and receiving devices by precisely
defining how the message will be sent across the communication
device.
COMMUNICATION SYSTEMS
Communication Channel
This is the actual connecting or transmission medium that carries the message. It can be
physical wire or cable, or it can be wireless.
COMMUNICATION CHANNELS
Communication Channels are essential elements of
every communication system. These channels
carry out the data from one computer to another.
COMMUNICATION CHANNELS
Two Categories
Physical ConnectionWireless Connection
COMMUNICATION CHANNELS
Physical Connection
It uses a solid medium to connect sending and
receiving devices.
COMMUNICATION CHANNELS
COMMUNICATION CHANNELS
Twisted-Pair Cable consists of pair of copper wires that
are twisted together.
Shielded Twisted-Pair (STP) Unshielded Twisted-Pair
(UTP)
COMMUNICATION CHANNELS
Coaxial Cable, a high frequency transmission
cable, replaces the multiple wires of telephone lines
with a single solid-copper core.
COMMUNICATION CHANNELS
Fiber Optic Cable transmits data as pulses of light
through tiny tubes of glass, and rapidly replacing
Twisted-Pair cable telephone lines.
COMMUNICATION CHANNELS
Fiber Optic Cable has over 26,000 times the
transmission capacity of Twisted-Pair Cable.
Compared to Coaxial Cable, it is lighter, faster, and more reliable in transmitting data.
WIRELESS CONNECTIONS
They move data through the air and use radio
waves to communicate.
WIRELESS CONNECTIONS
BluetoothWireless Fidelity (Wi-Fi)
MicrowaveWiMax
Long Term Evolution (LTE)Satellite
WIRELESS CONNECTIONS
Bluetooth is a short range communication standard that transmits data over short distances of up to approximately 33 feet.
WIRELESS CONNECTIONS
Wireless Fidelity (Wi-Fi) uses high-frequency radio signals to transmit data. Most home and business
wireless networks use Wi-Fi.
WIRELESS CONNECTIONS
Microwave communications uses high-frequency radio
waves. It is sometimes referred to as line-of-sight communications because it can only travel in a straight
line.
WIRELESS CONNECTIONS
WiMax, Worldwide Interoperablity for
Microwave Access, is a new standard that extends the range of Wi-Fi networks
using microwave connections.
WIRELESS CONNECTIONS
LTE, Long Term Evolution, the newest wireless
standard, promises to provide greater speed and quality transmission in the
near future.
WIRELESS CONNECTIONS
Satellite Communication uses satellites orbiting
about 22,000 miles above the earth as microwave
relay stations.
WIRELESS CONNECTIONS
Many of these are offered by Intelsat, the International
Telecommunications Satellite Consortium, owned by 114 governments and forms a worldwide communication
system.
WIRELESS CONNECTIONS
UPLINK is a term relating to sending data to satellite.
DOWNLINK refers to receiving data from
satellite.
WIRELESS CONNECTIONS
Global Positioning System (GPS) is one of the most interesting application of Satellite Communications.
CONNECTION DEVICES
Telephones typically send and receive Analog
Signals.
Computers send and receive Digital Signals.
ANALOG AND DIGITAL SIGNALS
MODEMS
The word MODEM is short for MOdulator-DEModulator.
It enables digital microcomputers to
communicate across different media.
MODEMS
Modulation is the process of converting from digital to
analog.
Demodulation is the process of converting from analog to
digital.
TRANSFER RATE
This is the speed by which modems transmit data.
MODEMS
Four Commonly Used Modems
TelephoneDigital Subscriber Line (DSL)
Cable ModemWireless Modem
MODEMS
MODEMS
A Telephone Modem is used to connect a
computer directly to a telephone line. It can either be internal or
external.
MODEMS
A Digital Subscriber Line Modem uses standard phone lines to create a high-speed connection directly to your phone
company’s office.
MODEMS
A Cable Modem uses the same coaxial cable as your
television and creates a high-speed connection.
MODEMS
A Wireless Modem, also known as WWAN (Wireless
Wide Area Network), usually uses a small plug-in USB or
ExpressCard device that provides very portable wireless connectivity.
CONNECTION SERVICES
Dial-Up ServiceDigital Subscriber Line (DSL)
Asymmetric DSL (ADSL)Cable Service
Satellite Connection ServiceCellular Service
DATA TRANSMISSION
Bandwidth is a measurement of the width or capacity of the
communications channel. Effectively, it means how much information can move across the communication channel in
a given amount of time.
DATA TRANSMISSION
Four Categories of Bandwidth
VoicebandMedium Band
BroadbandBaseband
DATA TRANSMISSION
Voiceband, also known as low bandwidth, is used for
standard telephone communication.
DATA TRANSMISSION
Medium Band is used in special leased lines to
connect midrange computers and mainframes as well as to
transmit data over long distances up to a very high
speed transfer rate.
DATA TRANSMISSION
Broadband is widely used for DSL, cable, and satellite
connections to the Internet. Several users san
simultaneously use a single broadband connection for high-speed data transfer.
DATA TRANSMISSION
Baseband is widely used to connect individual computers that are located close to one another. Though it is able to
support high-speed transmission, it can only carry
a single signal at one time.
PROTOCOLS
Protocols are sets of communication rules for the
exchange of information.
HTTP and HTTPSTCP/IP
PROTOCOLS
TCP/IP (Transmission Control Protocol / Internet Protocol) involves identifying sending and receiving devices, and breaking information into
small parts for transmission across the Internet.
NETWORKS
A Computer Network is a communication system
that connects two or more computers so that they
can exchange information and share resources.
SPECIALIZED NETWORKS TERMS
Node / Client / ServerDirectory Server / Host
Router / SwitchNetwork Interface Card (NIC)Network Operating System
(NOS)Network Administrator
SPECIALIZED NETWORKS TERMS
Node is any device that is connected to a network. It
could be a computer, printer, or data storage
device.
SPECIALIZED NETWORKS TERMS
Client is a node that requests and uses
resources available from other nodes. Typically, a
client is a microcomputer.
SPECIALIZED NETWORKS TERMS
Server is a node that shares resources with other nodes. Depending on the task they may be called an application
server, communication server, file server, printer server,
database server, or web server.
SPECIALIZED NETWORKS TERMS
Types of Server
Centralized ServerDedicated Server
SPECIALIZED NETWORKS TERMS
Directory Server is a specialized or dedicated
server that manages resources, such as user accounts, for an entire
network.
SPECIALIZED NETWORKS TERMS
Host is any computer system that can be
accessed over a network.
SPECIALIZED NETWORKS TERMS
Router a node that forwards or routes data
packets from one network to their destination in
another network.
SPECIALIZED NETWORKS TERMS
Switch is a central node that coordinates the flow
of data by sending messages directly between sender and receiver nodes.
SPECIALIZED NETWORKS TERMS
A hub previously filled the role of a switch by sending a received message to all connected nodes, rather than just the intended
node.
SPECIALIZED NETWORKS TERMS
A Network Interface Card (NIC) is an expansion card
located within the system unit that connects the computer to
a network. It is sometimes referred to as LAN Adapter.
SPECIALIZED NETWORKS TERMS
A Network Operating System (NOS) controls and coordinates the activities of all computers and other
devices on a network.
SPECIALIZED NETWORKS TERMS
A Network Administrator is a computer specialist
responsible for efficient network operations and implementation of new
networks.
NETWORK TYPES
Home NetworkPersonal Area Network
Local Area NetworkWireless LAN
Metropolitan Area NetworkWide Area Network
NETWORK TYPES
Home Network is commonly used by
individuals in their homes and apartments and can be connected in a variety
of ways.
NETWORK TYPES
Personal Area Network is a type of wireless network that works within a very
small area, such as cellphone to headset,
keyboard to cellphones, PDAs to other PDAs.
NETWORK TYPES
Local Area Network is a computer network with nodes that are in close
physical proximity, within the same building for
instance.
NETWORK TYPES
Wireless LAN is a Local Area Network that typically uses radio frequencies to connect computers and other devices.
All communications pass through the network’s Wireless Access Point or Base Station.
NETWORK TYPES
Metropolitan Area Network spans distances up to 100 miles and are frequently
used to link between office buildings that are located
throughout a city.
NETWORK TYPES
Wide Area Network is a countrywide and worldwide
network, typically spans distances greater than 100 miles, and uses microwave
relays and satellites to reach users over long distances.
NETWORK TYPES
The primary differences between the network
types is the geographic range.
NETWORK ARCHITECTURE
Network Architecture describes how a network
is arranged and how resources are coordinated
and shared.
NETWORK ARCHITECTURE
Bus TopologyRing TopologyStar TopologyTree TopologyMesh Topology
NETWORK ARCHITECTURE
In Bus Topology, each device is connected to a common cable called a
bus or backbone, and all communications travel
along this bus.
NETWORK ARCHITECTURE
In Ring Topology, each device is connected to two
other devices forming a ring. When a message is
sent, it is passed around the ring until it reaches the intended destination.
NETWORK ARCHITECTURE
NETWORK ARCHITECTURE
In Star Topology, each device is connected directly to a central network switch.
Whenever a node sends a message, it is routed to the switch, which then passes
the message to the recipient.
NETWORK ARCHITECTURE
NETWORK ARCHITECTURE
In Tree Topology, each device is connected to a
central node, either directly or through one or more other devices. It is also known as Hierarchical
Network.
NETWORK ARCHITECTURE
NETWORK ARCHITECTURE
In Mesh Topology, each node is required to have
more than one connection to the other nodes and
does not require a specific physical layout.
NETWORK ARCHITECTURE
NETWORK STRATEGIES
Client/Server NetworkPeer-to-Peer Network
NETWORK STRATEGIES
Client/Server Network uses central computers to
coordinate and supply services to other nodes on
the network.
NETWORK STRATEGIES
NETWORK STRATEGIES
In a Peer-to-Peer (P2P) Network, nodes have
equal authority and can act as both client and
server.
ORGANIZATIONAL NETWORKS
An Intranet is a private network within an organization
that resembles the Internet.
An Extranet is a private network that connects more
than one organization.
ORGANIZATIONAL NETWORKS
NETWORK SECURITY
A firewall consists of hardware and software that
control access to a company’s intranet and other internal networks, through a special software of computer
called Proxy Server.
NETWORK SECURITY
Intrusion Detection System (IDS) works with firewall to protect and organization’s network. It can recognize signs of network attack by
pattern matching and heuristics.
NETWORK SECURITY
A Virtual Private Network (VPN) create a secure
private connection between a remote user and an organization’s
internal network.