Chapter 4

The internet

("The Net") is a global WAN that connects approximately 1 million organizational computer networks in more than 200 countries on all continents, including Antarctica.

Network

System of connected nodes, can be people, computers and other devices, organizations, and ideas.

What is TCP/IP?

The protocol of the internet.

Bandwidith

The transmission capacity of a network; it is stated in bits per second. Ranges from narrowband to broadband.

What is hpertext?

The underlying concept defining the structure of the World Wide Web.

What is VOIP?

(Voice-over-Internet Protocol)- The use of the Internet as the transmission medium for telephone calls.

What is an Internet Service Provider (ISP)?

A company that provides Internet connections for a fee.

Wide Area Network (WAN)

A network that covers a large geographical area. Typically connects multiple LANs. Example: the internet

Intranet

A network that uses Internet protocols so that users can take advantage of familiar applications and work habits.

Packets

A piece of message sent as a part of the bigger message.

IP addresses

Involves its own unique i.d. for each device. Acts as a ZIP code.

Data Communications

Movement of data from one node to another.

Network Protocol

Nodes work together by adhering to a common set of rules and procedures known as protocol.

What is a uniform resource locator (URL)?

Points to the address of a specific resource on the web.

What is the World Wide Web (www)?

A system of universally accepted standards for storing, retrieving, formatting, and displaying information via a client/server architecture.

Computer Network

A system that connects computers and other devices (e.g. printers) via communications media so that data and information can be transmitted among them.

What is a portal?

A web-based personalized gateway to information and knowledge that provides information form disparate information systems and the Internet, using advanced search and indexing techniques.

Router

Communication processor that routes messages from a LAN to the Internet, across several connected LANs, or across a wide area network such as the Internet. Can also connect computers to other computers, direct messages to destination. (Post office)

Clients

Computer that depends on bigger computer to send messages.

Switch

Connects computers to router. (How you get to the post office)

Extranet

Connects parts of the intranets of different organizations. Enables business partners to communicate securely over the Internet using virtual private networks (VPNs).

Local Area Network (LAN)

Connects two or more devices in a limited geographical region, usually within the same building, so that every device on the network can communicate with every other device.

Analog signals

Continuous waves that transmit information by altering the characteristics of the waves. 2 parameters: Amplitude and frequency. Amplitude-higher=louder, Frequency-closely packed=higher pitch. Analog signals tend to be more continuous than digital, they oscillate smoothly, and can tell a story.

Wireless media (broadcast media)

Data transmissions over electromagnetic media-the "airwaves".

HTTP

Defines how messages are formulated and how they are interpreted by their receivers.

Digital signals

Discrete pulses that are either on or off, representing a series of bits (0s and 1s). Digital signals tend to oscillate more rapidly than analog signals, they use binary code, and give only two options: yes or no.

What is a network access point (NAP)?

Exchange points for Internet traffic. They determine how traffic is routed. NAPs are key components of the Internet backbone.

Modem

Function is to convert digital signals to analog signals, a process called modulation, and analog signals to digital signals, a process called demodulation. Gets name from modulator-demodulator.

What is a browser?

Provides a graphical front end that enables users to point-and-click their way across the web, called surfing. Users access the Web through software applications called browsers.

Server

Serves the client. The bigger, central computer.

What is unified communications? Examples?

Simplifies and integrates all forms of communications-voice, voice mail, fax, chat, email, instant messaging, short message service, presence (location) services, and videoconferencing-on a common hardware and software program. Ex: Reading a voice mail as an email.

Why do organizations need data communication networks?

They allow organizations to become more flexible so that they can adapt to rapidly changing business conditions. Networks allow companies to share hardware, computer applications, and data across the organization and different organizations. Graphically dispersed employees can share.

Node

Things that send or receive data. Ex: person, computer.

Telecommunications

Type of data communication, typically over far distances.

Wireline media (cable media)

Use physical wires or cables to transmit data and information.