Upload
damon-phillips
View
216
Download
0
Tags:
Embed Size (px)
Citation preview
TELECOMMUNICATIONSNetworks & the Internet
TELECOMMUNICATIONS
Communicating and transmitting information electronically
(includes transmitting data, text, pictures, voice and video over long distance)
HOW DO WE “TELE-”COMMUNICATE? Phone Voice mail Cell phone—also includes texting Fax—a document generated by using a facsimile
machine Email—transmission of messages and files using a
computer network Instant messaging
METHODS OF TELECOMMUNICATION Social networking sites—websites that provide a
virtual community in which people with a shared interest may communicate
Telecommuting—the action of working from home using a computer and telecommunications media
Intranet—a company’s private computer network e-commerce/e-business—buying/selling
merchandise or conducting business on the Internet
METHODS OF TELECOMMUNICATION Audio conferencing—Communication between three
or more sites that are linked by a voice-only telecommunications medium
Video conferencing—Communicate in real time via video with two or more people at different locations
TELECOMMUNICATIONS & NETWORKS
At the heart of telecommunications is the ability to “network” computers together . . .
And at the heart of networks is the media through which communication flows: wires, telephone
lines, or wireless signals.
BENEFITS OF NETWORKS
Instant communication
Information sharing Hardware sharing Software sharing
NETWORK
A group of two or more computers linked together
NETWORK COMPONENTS
Server—the computer at the center of a network that manages network resources; more powerful than a desktop computer
Client—any computer on a network that relies on a server for resources, i.e. email, etc.
computers that are connected and ready to receive and/or transmit data are said to be online,
as opposed to a stand-alone computer: a computer that is not connected to a network
CLASSIFICATION BY COVERAGE Local Area Networks—a network that
spans a relatively small area; typically is confined to a single building or several buildings
WAN—a network that geographically spans a large area; typically includes 2 or more LANs There are several variations of WANs
A popular WAN used by large businesses is the VPN
VIRTUAL PRIVATE NETWORK VPN—a private network that uses a public
network (usually the Internet) to connect remote sites or users together.
Instead of using a dedicated, real-world connection such as leased line, a VPN uses "virtual" connections routed through the Internet from the company's private network to the remote site or employee.
WHAT MEDIA IS USED TO CONNECT COMPUTERS TO A NETWORK OR TO THE INTERNET?
Two categories of media Wired Media Wireless Media
A computer will need a network interface card (NIC)
to connect to a network or the Internet.
WIRED MEDIA
Twisted pair cable—cable that consists of two independently insulated wires twisted around one another. Twisted pair is the least expensive type of wire
Coaxial cable—a type of wire that consists of a center wire surrounded by insulation and then a grounded shield of braided wire
Fiber optic cable—a technology that uses glass (or plastic) threads (fibers) to transmit data. Fiber optics provide the best quality but is expensive to install and the cable is more fragile and difficult to splice
WIRELESS MEDIA
Microwave Satellite Infrared (remote controls)
Cellular Wi-Fi (radio waves)
Bluetooth (short-range radio waves)
HOW IS INFORMATION TRANSMITTED TO AND FROM YOUR COMPUTER ON A NETWORK OR THE INTERNET? Modems—phone, cable, DSL
Satellites—provides high speed access for rural, remote areas or mobile vehicles and boats; transmits electromagnetic signals
T Lines—a digital high-speed long-distance telephone line that is capable of carrying multiple types of signals across the line; T-1 / T-4 lines are currently available; typically large companies and organizations qualify
WHAT IS THE INTERNET?
A global network that connects millions of computers all over the world. The Internet backbone is the central network that
links all the parts of the Internet together.
HOW DO WE GET ACCESS TO THE INTERNET?
Internet Service Providers (ISP)—businesses that sell Internet access to customers
What ISPs are available in our area?
WHERE DO THE ISPS GET ACCESS?
NSP—Network Service Providers supply direct backbone access to ISPs, who then sell access to their customers. Example: AT&T, Verizon, Sprint are major NSPs
in the US
WHAT IS THE WORLD WIDE WEB?
A system of computers that allows you to communicate with other computers talking the same language (using the same protocol)
WHAT IS “PROTOCOL”?
Protocol—rules for communicating between two electronic devices
Internet Protocol (IP)—rules for communicating on the Internet
Hypertext Transfer Protocol (HTTP)—rules for transferring web pages on the Internet
PROTOCOL
Simple Mail Transport Protocol (SMTP)—protocol used for transmitting electronic mail
File Transfer Protocol—a protocol designed to transfer files between an FTP server and a computer—example: downloading software
Voice Over Internet Protocol (VOIP)-- is a digital telephone service that allows you to make and receive phone calls over the internet instead of through the phone lines.
WHAT DOES URL STAND FOR? Uniform Resource Locator
It specifies the internet address of a file stored on a host computer
Example: http://ncaasports.com/basketball/mens/
scoreboard.htm
URL VS DNS
Computers use a domain name system to translate URLs into numeric addresses
WHAT IS THE NUMERIC ADDRESS CALLED?
Internet Protocol address: the numeric address assigned to EVERY computer or device that connects to the Internet
An IP address is a four-part number, each part consisting of a digit from 0 to 255. Example: 207.46.192.254
WHAT IS THE FORMAT OF A URL?
Protocol – host – path – filename
Example: http://www.d1baseball.com/conferences/standings_sec.htm
Protocol: http:// Host: www.d1baseball.com Path: conferences Filename: standings_sec.htm
WHAT IS A TLD:
TLD – Top level domain; suffix at the end of a web address .com—commercial; generic .edu—educational institution—higher ed .gov—state or federal government .mil—U.S. military .net—network service provider (can be used generically) .org—usually nonprofit but can be generic .pro—professional—like physicians, lawyers, CPAs, etc. .name—reserved for individuals
WHAT IS A COUNTRY CODE? A domain name that identifies the location
of a server Example:
.us—United States .jp—Japan .uk—United Kingdom .ca—Canada .mx—Mexico
Find country codes for the following: Brazil, Egypt, Jamaica, Cayman Islands