This document provides an overview of computer networking and telecommunications. It discusses how networks allow hardware, software, and people to be connected. It describes the basic anatomy of networks, including network interface cards and modems. It also discusses different types of networks like local area networks and wide area networks. Additional topics covered include electronic mail, bulletin boards, teleconferencing, and emerging technologies like video conferencing and electronic funds transfer.

1. CIBM BUSINESS
INFORMATION SYSTEMS
Chapter Seven- Networking and Tele
-Communications

2. 7.1 LINKING UP: NETWORK
BASICS
 A computer network is any computer system that
links together two or more computers. The
reason networking is important revolves
around the three essential components of every
computer system:
 Hardware. Networks allow people to share computer
hardware, reducing costs and making it possible for
more people to take advantage of powerful computer
equipment.
 Software. Networks allow people to share data and
software programs, increasing efficiency and
productivity.
 People. Networks allow people to work together in
ways that are otherwise difficult or impossible.

3. NETWORK HUB AND TOPOLOGY
EXAMPLE

4. 7.1.1 BASIC NETWORK ANATOMY
 A network extends the range of computer
electrical pulses, allowing them to travel to other
computers. A computer may have a direct
connection to a network or it might have remote
access to a network through a phone line
and a dial-up connection. The Network
Interface
 Personal computers communicate through serial
ports with other computers. IBM-
compatible PCs require a network interface
card (NIC) containing the necessary serial
port.

5. COMMUNICATION À LA MODEM
 The telephone network is ideal for connecting remote computers, too,
except it was designed to carry sound waves, not streams of bits.
Before a digital signal—a stream of bits—can be transmitted
over a standard phone line, it must be converted to an analog
signal—a continuous wave.
 At the receiving end, the analog signal first must be converted back
into the bits representing the original digital message. Each of these
tasks is performed by a modem (short for
modulator/demodulator)—a hardware device that connects a
computer’s serial port to a telephone line. A modem converts a
computer’s digital signals into analog signals. The analog waves are
transmitted through telephone lines to another modem, which
converts them back into digital signals.
 An internal modem is installed on a circuit board inside the
computer’s chassis. An external modem sits in a box linked to the
computer’s serial port. Both types use phone cables to connect to the
telephone network through standard modular phone jacks. Modems
differ in their transmission speeds, measured in bits per second
(bps).

6. EXAMPLE OF TWO PC’S CONNECTED TO A
NETWORK HUB AND EXAMPLE OF
WIRELESS MODEM

7. 7.1.2 NETWORKS NEAR AND FAR
 A local area network (LAN) is a network in which the
computers are close to each other, usually in the same
building. Cables serve as information highways for
transporting data between devices.
 A typical local area network includes a collection of computers and
peripherals; each computer and shared peripheral is an individual
node on the network. In a wireless network each computer
has a tiny radio connected to its serial port so it can send and
receive data through the air rather than through cables.
 All computers on a LAN do not have to be the same brand, or use the
same operating system. Most organizations depend on network
administrators to take care of the behind-the-scenes details so others
can focus on using the network.
 A wide area network (WAN), as the name implies, is a network
that extends over a long distance. Wide area networks are
possible because of the web of telephone lines, microwave
relay towers, and satellites that span the globe. Some WANs
are private operations. Others are public or semi - public
networks.

8. 7.2 ELECTRONIC MAIL AND
TELECONFERENCING: INTERPERSONAL
COMPUTING
 Electronic mail (e-mail) systems allow users to send
messages (mail) from one computer to another. Each
user has a mailbox—a storage area for messages.
Users select a login name or screen name—the one-
word or phrase name they have chosen to identify the
user on the screen. A user then enters a password—a
string of letters and numbers known only by the user—
and as it is typed only asterisks appear on the screen.
 A variation of electronic mail is the teleconference—
an on-line meeting between two or more people. Many
teleconferencing systems allow users to communicate
in real time, just as they would by telephone. In a
real-time teleconference, each participant sits at a
computer or terminal, watching the meeting
transcript scroll by on the screen and typing
comments on the keyboard.

9. 7.3.1 ELECTRONIC BULLETIN
BOARD SYSTEMS (BBSS)
 An electronic bulletin board system (BBS) is a place
for posting messages and reading messages left by
others. BBS software allows the computer to receive,
organize, and post messages in appropriate
categories automatically.
 Many BBSs operate without human supervision for long
periods of time. The system operator, or sysop, is needed
only for occasional maintenance and troubleshooting.
 Many BBSs divide messages into categories called SIGs,
for special interest groups.
 In addition, many bulletin boards serve as repositories for
public domain software and shareware—two types of
software that can be freely distributed without violating
copyright laws.
 BBS users can download software—copy it from the
BBS computer to their computers— and upload
software—post it on the BBS so it’s available for
others. Software

10. 7.4 TELECOMMUNICATION TRENDS:
MERGING AND EMERGING
TECHNOLOGIES
 7.4.1 Alternative Communication Technologies
 The following forms of telecommunication don’t require
users to type commands and messages.
 Facsimile Transmission
 A facsimile (fax) machine is a fast and convenient
tool for transmission of information stored in paper
documents, such as typed letters, handwritten notes,
photographs, drawings, book pages, and news
articles. A computer can send on-screen documents
through a fax modem to a receiving fax machine.
The fax modem translates the document into signals
that can be sent over phone wires and decoded the
receiving fax machine. A computer can also use a fax
modem to receive transmissions from fax machines,
treating the sending fax machine as a kind of remote
scanner. Before a faxed document can be edited, it
must be processed by optical character recognition
(OCR) software.

11. VOICE MAIL AND COMPUTER
TELEPHONY
 A voice mail system is more than an
answering device; it’s a sophisticated
messaging system with many of the
advantages of e-mail. Computer telephony
software and hardware allow a personal
computer to serve as a speakerphone,
answering machine, and even as a voice
mail system. Video Teleconferencing
 A video teleconference allows people to
communicate face to face over long
distances by combining video and computer
technology. Video teleconferencing comes
to the desktop with video phones and video
teleconferencing software.

12. ELECTRONIC FUNDS TRANSFER
(EFT)
 Money, like other digital information, can be
transmitted through computer networks. That’s why
it’s possible to withdraw cash from your checking
account using an automated teller machine (ATM) at
a bank, airport, or shopping mall thousands of miles
from your home bank. An ATM is a specialized
terminal linked to a bank’s main computer through a
commercial banking network. Many people have
paychecks deposited automatically in checking or
savings accounts and have bills paid automatically
out of those accounts. Electronic funds transfer is one
component of electronic commerce, or e-commerce
—commercial activity that takes place through
networked computers.
 Personal Digital Assistants

13. PERSONAL DIGITAL ASSISTANTS
 Many personal digital assistants (PDAs)
combine cellular phone, fax modem, an
electronic mailbox, a pager, and other
communication equipment in a lightweight
box. These devices are popular with a
growing number of mobile professionals.

14. 7.4.2 CONVERGING
COMMUNICATION
TECHNOLOGIES
 ISDN
 The Integrated Services Digital Network, commonly called
just ISDN, will link telephones, computers, fax
machines, television, and even mail in a single
digital system. ISDN is already available in a few
cities, but most phone lines can’t handle ISDN. The
main problem is bandwidth—the quantity of
information that can be transmitted through a
channel in a given amount of time. The bandwidth
bottleneck disappears when copper phone lines are
replaced with high-capacity fiber optic cables. Fiber
optic cables use light waves to carry information at
blinding speeds.
 Digital Communication Comes Home
 Integrated digital communication lines will eventually find
their way into our homes, radically changing our lives in
the process.

15. END THANK YOU