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45 Cards in this Set
- Front
- Back
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Any system of two or more computers that are linked together |
Computer Network |
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3 things why networking is important: |
1. people share computer hardware -- thus reducing cost 2. people share data + software programs -- increase efficiency and production 3. people work together in ways that are otherwise difficult/impossible |
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What's Arthur C. Clarke's prophecy? |
Predicted "geostationary communications satellites" -- satellites that relay wireless transmissions between locations on planet |
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What is Global Positioning Systems (GPS) -- 4 things |
1. developed by Department of Defense 2. include 24 satellites that circle Earth 3. each satellite contains computer + atomic clock + radio 4. on ground, GPS receiver use signals broadcast by 3-4 satellites to determine its position |
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Computers that are physically close to each other, usually same buidling |
Local Area Network (LAN) |
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Contains nodes which each have a tiny radio transmitter connected to its network port |
Wireless Network |
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What does Wireless Network do (4 things) |
1. sends + receives data through air rather than cables 2. computers are linked w/in a building or cluster of buildings 3. each computer + peripheral is an individual node on network |
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Links 2 or more LANs within a city |
Metropolitan Area Network (MAN) |
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This extends over long distance where where each network site is a node on the network |
Wide Area Network (WAN) |
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data transmitted over common pathways in WAN |
backbone |
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[communication freq. happens between LANs and Wans]
Quantity of info that can pass through a communications |
Bandwidth |
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Hardware devices that can pass messages between networks |
Bridges + Gateways
== often translate messages so they can be understood by networks + obey different software protocols |
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Hardware devices or software programs that route messages as they travel between networks |
Routers |
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An alternative to traditional networks, creates individual nodes for communication |
Mesh Networks -- used for small, temp. comm systems (ex: emergency) |
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Permits direct network connection |
Network interface hardware |
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What Network Interface Hardware controls: |
flow of data between computer's RAM and the network hardware |
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Common types of networks require some kind of: |
Ethernet port |
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What is Ethernet port? (3 things) |
1. networking architecture developed in '76 at Xerox 2. all new PCs include an Ethernet port 3. tablets + laptops don't Ethernet -- rely on wireless connectivity |
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Hardware device that connects a computer's serial port to a telephone line (for remote access) |
Modem |
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Modem's transition speed (measured in bits per seconds) |
28,000 bps - 56.6k bps |
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Basic Network Anatomy (2 things) |
1. computer sends signals 2. model coverts digital sings to analog to be transmitted through telephone lines |
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connection with much greater bandwidth than modems have |
Broadband Connection |
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Use standard phone lines, provided by phone companies |
DSL |
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Provide fast network connections through cable tv networks |
Cable modems |
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Can connection computers to networks using radio waves rather than wires |
high-speed wireless connections |
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can deliver fast computer network connections as well as tv programs |
satellite dishes |
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replacing copper wires in worldwide telephone network |
fiber optic cables |
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what fiber optic cables do |
rapidly and reliable transmit masses of multimedia data at same time it's handling voice messages (1-25 mi) |
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Named after Danish king, overcomes differences between mobile phones, handheld computers, and PCs, making it possible for all devices to communicate regardless of OS |
Bluetooth |
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With bluetooth, possible to create a ________ - a network that links variety of personal electronic devices so they can communicate with each other |
personal area network (PAN) |
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future possibilities of bluetooth |
1. pacemaker that sense a heart attack, notifies victim 2. radio communicates w/ parking-lot video cameras to find where spaces are available |
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set of rules of exchange of data between a terminal and a computer |
Protocol |
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establishes protocol that is followed by computer's hardware |
communication software |
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handles communications between many workstations |
network operating systems (NOS) |
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one or more computers act as dedicated servers and all the remaining computers act as clients |
client-server model |
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model where every computer on network is both client and server |
p2p (peer to peer) model |
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enables you to send/receive messages to others on the network |
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what email systems based on older UNIX-based system require |
read/unread messages be stored on remote mail servers |
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enable you to participate in email discussion groups on special-interest topics |
mailing list |
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a public (or semi-public) discussion on a particular subject |
newsgroup or forum |
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contain only messages that have been filtered by designated moderators |
moderated forums |
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messaging system with ability to store, organize and forward messages |
voice mail |
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a growing trend - linking of computers and telephones to gain productivity |
computer telephony integration (CTI) |
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sends voice signals through internet, bypassing phone companies altogether |
VOIP - voice over internet protocol |
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bugs of VOIP |
1. caller-id can be faked 2. calling 911 doesn't show caller's location 3. outside US, some countries tax or criminalize VOIP 4. not legally secure against wiretapping |
