COB204 Chapter 4

Three basic types of peer-to-peer processing

(1) unused CPU power among networked computers (2) Real-time, person to person, collaboration such as Sharepoint (3) advanced search and file sharing

Backbone Network

(WAN) High Speed central networks to which multiple smaller networks connect (page 105 for figure)

Ethernet

A common LAN protocol

Digital Subscriber Line (DSL)

A type of broadband connection

Cable Modem

Access over your cable TV coaxial cable. Can have degraded performance if many of your neighbors are accessing the internet

Satellite

Access where cable and DSL are not available

Coaxial Cable Advantages/Disadvantages

Advantages: Higher bandwidth than twisted pair, Less susceptible to electromagnetic interference Disadvantages: Relatively expensive and inflexible, easily tapped, somewhat difficult to work with

Twisted Pair-wire Advantages/Disadvantages

Advantages: Inexpensive, Widely available, easy to work with Disadvantages: Slow, subject to interference, easily tapped (low security)

Fiber-optic cable Advantages/Disadvantages

Advantages: Very High bandwidth, relatively inexpensive, difficult to tap Disadvantages: Difficult to work with

Analog signals have two Parameters:

Amplitude and frequency

All sounds, including human voice, are ______

Analog

Networks transmit information with two basic types of signals:

Analog and Digital

Distance Learning

Any learning situation in which teachers do not meet students face-to-face

DSL

Broadband access via telephone

Communications channels are comprised of two types of media:

Cable, and broadcast

80% of internet users use 10 languages:

English, Chinese, Spanish, Japanese, German, Korean, French, Italian, Russian and Portuguese

Fiber-to-the-home

Expensive and usually placed only in new housing developments

Network access points NAPs

NAPs are exchange points for internet traffic

Bandwidth comes in two forms

Narrowband and Broadband

There are various types of computer networks; from smallest to largest:

Personal Area Networks (PANs), Local Area Networks (LANs), Metropolitan Area Networks (MANs), Wide Area Networks (WANs)

Internet Backbone

Primary network connections and telecommunications lines that link the nodes

Networks represent a compromise among three objectives:

Speed, distance and cost; you can usually get two of the three

Dial-up

Still used in the U.S. where broadband is not available

Wireline media or cable media

Use physical wires or cables to transmit data and information

Wireless

Very convenient; will increase the use of broadband wireless

Portal

Web-based, personalized gateway to information and knowledge that provides relevant info from different IT systems and the Internet using advanced search

Broadcast Media

Wireless media

Router

a communications processor <-- (important part) that routes messages from a LAN to the internet, across connected LANs, or across a WAN

Internet Service provider

a company that provides internet connections for a fee

Search Engine

a computer program that searches for specific information by keywords and the reports results

communication channel

a pathway that connects data from one location to another

DSL modems:

always maintain a connection so an internet connection is immediately available

Protocol

common set of rules and procedures

Peer-to-Peer processing

computer acts as both a client and a server

Embedded LANs

connect to the backbone of Backbone WAN

Hyperlink

connection from a hypertext file or document to another location or file

Extranet

connects parts of intranets of different organizations

Local Area Network (LAN)

connects two or more devices in a limited geographical region, usually within the same building (fast, cheap; can't go long distances)

Analog signals

continuous waves that transmit information by altering characteristics of the waves

Hypertext Transfer protocol (HTTP)

defines how messages are formulated and how they are interpreted by their receivers

There are three types of modems:

dial-up modems, cable modems, and DSL modems

IP is resonsible for:

disassembling delivering and reassembling data during transmission

Digital signals

discrete pulses that are either on or off, representing a series of bits (page 107)

Distributed processing

divides processing work among two or more computers

IP Address

each computer in the internet has an assigned address that distinguishes

Collaboration

efforts by two or more entities

Application layer

enables client application programs to access the other layers

Client/Server computing

links two or more computers in an arrangement in which computing services are provided

Workflow

movement of info as it progresses through the sequence steps that make up an organization's work procedures

Enterprise Network

multiple LANs and/or multiple WANs are interconnected to form an Enterprise Network

Wide Area Network (WAN)

network that covers a large geographical area... Typically connecting multiple LANs

Intranet

network that uses internet protocols so that the users can take advantage of familiar apps and work habits

corporate portal

offers a personalized, single point of access through a web browser to critical business information

affinity portal

offers a single point of entry to an entire community of affiliated interests

browsers

provide a graphical font end that enables users to point and clock their way across the web (Chrome or safari)

Servers

provide computing services for user PCs called clients

Bandwidth

refers to the transmission capacity of a network.

Industry wide portal

serves entire industries

Unified communications

simplifies and integrates all forms of communications

Uniform resource locator (URL)

specific resource on the web

work group

specifically two or more individuals who act together to perform some task

Computer Network

system that connects computers and other devices to so that information can be transmitted among them

Internet

the global WAN that connects everyone

A Commercial portal

the most popular type of portal on the internet; Intended for broad and diverse audience

Twister-pair wire

the most prevalent form of communications wiring; used for almost all business telephone wiring

broadband

the transmission capacity of a communications medium faster than 4 Megabits per second (relatively high network capacity)

Hypertext

the underlying concept defining the structure of the world wide web; displayed on a computer display or other electronic device with hyperlinks

The function of a Modem

to convert digital signals to analog signals - this is called (modulation) - and from analog to digital - demodulation

Crowdsourcing

type of collaboration in which an organization outsources a task to a group of people

Server

typically contains various software and data for the network

Internet Protocol

uses a suite of protocol to perform 3 basic functions: (1) Manage the movements of data packets between computers by establishing connection between computers (2) Sequence the transfer of packets (3) acknowledges the packets have been transmitted

Extranets offer limited accessibility to the intranets of participating companies as well as inter-organizational communications

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