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47 Cards in this Set
- Front
- Back
Globalization
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1.0- 1492-1800s - country's expanded globally
2.0- 1800s-2000s- companies expanded globally 3.0-2000s-present- web enabled collaboration globally between individuals |
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Triple Convergence
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Flatteners, billions moved into workplace, vertical workplace to horizontal workplace
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Other Triple Convergence
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9/11, Enron, Dot Com Bust
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Web 1.0
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Read Only
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Web 2.0
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User generated content
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7 Layer Model
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Physical Datalink, Network, Transport, Session, Presentation, Application
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5 Layer MOdel
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Physical , Datalink, Network, Transport, Application
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Datalink Layer
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Media access control, error control
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Network Layer
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Addressing/routing of messages. Adds/removes network layer hjeader
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Transport Layer
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Links to application layer, segmenting messages
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Protocols
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Sets of standardized rules to define how to communicate at each layer and how to interface wth adjacent layers
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Half Duplex
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data flows both ways, but one way at a time
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Full Duplex
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data flows both ways, both directions at same time
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Guided vs Unguided media
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guided-physical matters carries transmissions
unguided- wireless |
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Twisted Pair Wire
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Telephone/LANs
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Coaxial Cable
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used for cabl TV, digital transmissino
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Fiberoptic Cable
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light created by LED sent down thin glass or plastic fiber. Highly durable, secure, fast
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Frequency
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How often a wave repeats itself
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Serial Transmissions
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Sends bit by bit over a single wire, slow, long distances
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Parallell
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uses several wires, multiple bits at a time, short distances
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Modulation
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Modify carrier wave's fundamental characteristics to encode information
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Demodulation
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Extracting signal from carrier wave(MODEM).
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Peer to Peer Network
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all computers act as both clients and servers, no dedicated server used
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Switch
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better than a hub, faster, no collisions.
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Collision
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two computers send data at the same time, and it collides somewhere in the middle
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LAN Bottlenecks
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points in network where congestion occurs, happens in network service, or network circuit
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Access Point(AP)
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used instead of hubs, acts as repeater for wireless signals
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Directional Antenna
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Projects signal only in one direction- safer /more secure
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Omnidirectional
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transmit in all directions simultaneously-> most WLANs
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War Driving
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searching for Wifi in a moving vehicle
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SSID
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Service Set identifier, each access point has one, occasionally must know to contact but is often broadcasted, not secure
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Hidden Node
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Attempts to transmist data to another station, but does not realize 3rd party is already communicating with receipient, lost message/multiple retries
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WEP/WPA
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WEP- Wireless encryption protocol-easy to break
WPA- Wireless protected access |
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Wimax
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worldwide interoperability for microwave access. larger distance covered than wifi and cellular
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Contention in Ethernet Networks
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transmits whenever the circuit is free
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Error Detection Techniques
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parity checks- detects one bit errors, only catches 50%
checksum- 95% 0 adds decimals to each character in message cyclic redudancy check(CRC)_ 100% effective |
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Asynchronous Tranmission
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start/stop transmission--> transmits a little at a time when convenient
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Synchronous Transmission
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Sent all at once in a frame
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Transmission Efficiency
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move as many bits as possible with errors being minimized
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MAC Address
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On network card, unique hardware identifier
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IP v4 vs IP v6
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v4- 32 bit addresses v6- 32 byte addresses
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DNS-Domain Name Service
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used to determine IP addresses for a given URL
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TCP/IP
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most common on internet, error checking, handles larger files, compatible with variety of data
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Routing
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identify what a packet shuold take from sender to receiver
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Routing table
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makes routing decisions, shows which path to send packets on to reach destination. each computer has its own routing table
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Dynamic Routing(Most common)
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uses routing tables at each node that are updated dynamically
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Centralized/Decentralized Routing
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centralized decisions made by one computer, decentralized made by each node
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