MGT318 Chapter 6

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amount of data can be transferred from one point to another in a certain period of time

loss of power in a signal as it travels from the sender to receiver notion that the pulse of electricity that is sent out to give info will eventually fade

multiple pieces of data, sent simultaneously to increase the transmission rate

voice-grade transmission channel capable of transmitting a limited amount of info

Rules that govern data communication:>Error detection>Message length>Transmission speed

1.

Input/output device (doesn't actually process the data)2. Terminal (connects to a comp where processing is done; relies fully on network)------iphone------3. Personal computer/ notebook (can do processing themselves; sends it out on network)4. Mainframes and supercomputers (alllll of the processing!)*processing levels increase as we go down the list

Transmission media:1. Conducted2.

Radiated

-->Wires/ twisted pair (STP & UTP) (telephone and computer chargers)-->Coaxial Cable (more insulated but low control, can be tapped and is susceptible to disruption)-->Fiber Optic (fast and more secure, but expensive and breakable)

-->Infrared (light beams; ex a remote control but it must be point directly at object)-->Radio frequencies (goes through walls)-->Cellular Networks-->Microwave (pulls one signal in, sends one out. limited to how far they will go because of Earth's shape; must be within 30 miles from each other)

devices that connect a computer to the internettypes: -dial up - digital subscriber line (DSL) -cable satellite tv does NOT require a modem

agreed on methods and rules that are standardized for -->Hardware connections -->Data transmissions -->File transfers (Wifi, Ethernet)they specify the format of message packets sent between computers

*packet*- a collection of binary digits sent from a computer to computer over a network *routing*- the process of deciding which path the data takes a. static (stays the same) b. dynamic (changes)Always send 2 packages on different routes just in case one doesn't get there

7 layers:ApplicationSessionPresentationTransport-------NetworkPhysical Data Link One side creates packet, the other side is creating a message

Transmission Control Protocol--establishes a link between hosts--ensures message integrity, sequencing and acknowledging packet delivery--regulates data flow between source and destination nodes

Internet Protocol- responsible for packet forwarding---Network address---Node addressOn the same side of the body

Local, Wide, Metropolitan

Star, Ring, Bus, Heirarchical, Mesh

-networks that exist within an operational facility-they are considered within local operational control

-much larger than LAN-connect computers that are miles apart

-a set of connected networks within the same city or metropolitan area but not in immediate proximity to each other-network that operates over a college campus or city

Software runs on the local computer and communicates with the remote server to request information or services -->Server is a remote computer on the network that provides information or services in response to request

PresentationApplicationData Management

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the client communicates directly with the servereffective in small workgroupsAdvantage: consists of application development speed, simplicity, and powerDrawback: changes in application logic require modifications of clients resulting in upgrade and modification costs

balance the workload between client and server by removing application processing from the client and server and placing it on a middle-tier server(three-tier architecture)Advantage: improved network performanceDrawbacks: consists of more network traffic and testing software is difficult

-Mobility-Flexibility-Ease of installation-Low cost

-Limited throughput-Limited range-In-building penetration problems -Vulnerability to frequency noise-Security