IS Chapter 4

World Wide Web

- An application that uses the transport functions of the internet. The Internet supports WWW -A system of universally accepted standards for storing, retrieving, formatting, and displaying information via a client/server architecture.

Network Access Points (NAP's)

-Access points connect internet service providers together -Computers that act as exchange points for Internet traffic and determine how traffic is routed

Networking computer systems

-Allow an organization to be more flexible and adapt to business conditions. -Allow companies to share hardware, computer apps and data across different org.s -Make it possible for geographically dispersed employees to share ideas.

Cloud Computing

-Computing and storage capacity as a service -Infrastructure (servers) -Platforms (software) -Software (apps and databases) -Applications are accessed through a browser

Cellular Wireless Media Channels

-Divide the geographic area into small areas/cells -Each cell has transmitter or radio relay antenna to send messages from one cell to another

Internet

-Functions as a transport mechanism -Made of wires and routers -A network of networks... a global WAN that connects approximately 1 million organizational computer networks in more than 200 countries and has become so widespread that it features in the daily routine of nearly 2.5 billion people.

Metropolitan Area Network (MAN)

-Large computer networks that cover a metropolitan area -Fall between LAN and WAN

Bluetooth

-Radio signals less than 30 feet -Connect to PC like printer

RFID

-Radio signals less than 300 feet -Tags and readers identify model objects

Intranet

-network that provides the infrastructure for the web to exist; (hardware/software) A network that uses Internet protocols so that users can take advantage of familiar applications and work habits. Intranets support discovery (easy and inexpensive browsing and search), communication, and collaboration inside an organization.

TDL: Top Level Domain

.edu/.mil/.gov

Four Layers of the TCP/IP reference Model

1. Application Layer 2. Transport Layer 3. Internet Layer 4. Network Interface Layer

Three fundamental points about network computing

1. In modern org.'s computers don't work in isolation; they constantly exchange data with one another. 2. This exchange of data provides companies with a number of significant advantages. 3. This exchange can take place over any distance and over networks of any size.

Experts concerned that users will experience brownouts from 3 factors

1. Increasing number of people working online 2. Popularity of Web sites such as YouTube requiring large amounts of bandwidth 3. Demand for high def television delivered over the Internet

Three basic functions of Transmission Control Protocol

1. Manages the movement of data packets between computers by establishing a connection between the computers 2. Sequences the transfer of packets 3. Acknowledges the packets that have been transmitted

Digital Subscriber Line (DSL)

A broadband connection

Communications Channel

A pathway or medium communicating data from one location to another. Communications Media: is the physical media used to send data (twisted-pair wire, coaxial cable, fiber optic cable, satellite)

Coaxial Cable

A single strand of insulated copper wire. It is much less susceptible to electrical interference, and it can carry much more data than twisted-pair. It is commonly used to carry high-speed data traffic as well as television signals.

Peer2Peer processing

A type of client/server distributing process that allows two or more computers to pool their resources, making each computer a client and a server

Corporate Portal

A web site that provides a single point of access to critical business information located inside and outside an organization

Internet Protocol Address (IP address)

Assigned address that identifies a computer on the internet

Router

Communications processor that routes messages from a LAN to the Internet.

Communications Channel

Comprised of two types of media 1. cable (wire/fiber-optic) 2. Broadcast (microwave/satelite/radio)

Fiber-Optic Cable

Consists of thousands of very thin filaments of glass fibers that transmit information via light pulses generated by lasers. The fiber-optic cable is surrounded by cladding, a coating that prevents the light from leaking out of the fiber.

Analog Signals

Continuous waves that transmit information by altering the characteristics of the waves. -Two parameters= amplitude and frequency.

Modem (modulator-demodulator)

Converts digital signals to analog signals—a process called modulation—and analog signals to digital signals—a process called demodulation. (The name modem is a contraction of modulator-demodulator.)

Internet2

Develops and deploys advanced network applications -Designed to be fast, always on, everywhere, natural, intelligent, easy and trusted. -Not a separate physical network from the internet

Digital Signals

Discrete pulses that are either on or off, representing a series of bits (0s and 1s). Th is quality allows digital signals to convey information in a binary form that can be interpreted by computers.

Types of Network Processing

Distributed Processing: divides processing work among two or more computers which enables computers in different locations to communicate with one another via telecommunications. Client/Server Computing: Client/server computing links two or more computers in an arrangement in which some machines, called servers, provide computing services for user PCs, called clients. Peer-to-Peer (P2P) Processing: a type of client/server distributed processing where each computer acts as both a client and a server. Each computer can access (assigned for security purposes) all files on all other computers.

Use of internet

Electronic mail, web-based call centers, voice communication, Unified communications, collaboration, electronic teleconferencing

Client/Server Computin

Form of distributed processing where servers perform computing functions for end-user PC's (clients)

Backbone network

High-speed central networks where multiple smaller networks connect

Last Mile Problem

Internet service providers use fiber optic to provide backbone -But houses are connected via twisted pair wire -Bottleneck: Can't get benefit of the faster/better tech

Virtual Private Networking (VPN)

Method that creates private network connecting two computers together; strong security -Goes through internet

Analog and Digital Signals

Networks transmit information with these two types of signals.

DSL Modem

Operate on same lines as voice telephones and dial-up modems; always maintain a connection

Cable Modem

Operate over a coaxial cable (TV), offer broadband access

Browser

Provides a graphical front end that allows users to point and click across the Web (surfing)

modem

Purpose: -To convert digital signals to analog signals (modulation) -To convert analog signals to digital signal (demodulation) -Types: dial-up/cable/DSL

Wireless LANs (wifi)

Radio signals less than 300 feet

Communications Satellites

Serves as relay stations for communications signals -Uses microwave signals

Network Protocols

Set of rules and procedures governing transmission of data across a network Protocals: Interet; LANs- Ethernet/Wireless LAN WANs- DSL/T-carrier system

Networks represent a compromise of 3 objectives

Speed, distance, and cost

Domain Names

The name assigned t an internet site containing multiple parts separated by dots.

Personal Area Network (PAN)

The smallest type of computer network -Short range (a few meters) used for communication among one person (fitbit)

Wireless Media Channel: Terrestrial Microwave

Transmit high-speed radio signals in line-of-sight path

IP addresses

Uniquely identify computers network -Map to domains where resources are located

Dial-Up Modem

Used by U.S. telephone system to convert digital information to analog wave pattern.

Wide Area Network (WAN)

a network that covers a large geographical area. WANs typically connect multiple LANs -Provided by telephone companies and int. networks of global comm. service providers. -large capacity/combine mult. channels Ex: internet

Computer Network

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

Broadband

based on the Federal Communications Commission (FCC) 2010 definition, broadband is the transmission capacity of a communications medium; faster than 4 megabits per second

Extranet

connects parts of the intranets of different organizations which 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.

TCP Layer: Application Layer

enables client application programs to access the other layers, and it defines the protocols that applications use to exchange data.

Hyper Text Transport Protocol

http:// -An application protocol that defines how they are interpreted by there reciever

Enterprise Network

organizational interconnected networks consisting of multiple LANs and may also include multiple WAN's -Faster than 4 megabits per second (Mbps).

TCP Layer: Network Interface Layer

places packets on, and receives them from, the network medium, which can be any networking technology.

TCP Layer:Transport Layer

provides the application layer with communication and packet services.

Bandwidth

refers to the transmission capacity of a network; it is stated in bits per second. -Ranges from narrowband (low transmission capacity) to broadband (high trans cap)

TCP Layer: Internet Layer

responsible for addressing, routing, and packaging data packets.

Twisted-Pair Wire

the most prevalent form of communications wiring used for almost all business telephone wiring and As the name suggests, it consists of strands of copper wire twisted in pairs. It is relatively inexpensive to purchase, widely available, and easy to work with.