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38 Cards in this Set
- Front
- Back
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network
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a collection of computers that communicate with one another over transmissioin lines
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(LAN) Local Area Network
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connects computers that reside in a single geographic location on the premises of the company that operates the LAN. LAN IS A SINGLE LOCATION
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(WANs) Wide area networks
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connect computers at different geographic locations. The computers in two separate company sites must be connected using a WAN
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internet
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network of networks
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"the Internet"
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collection of networkds that you use when you send emailor access a Web site.
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switch
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a special purpose computer that recieves ans transmits messages on the LAN
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network interface card (NIC)
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each LAN has one. it conects the devices's circuitry to the cable.
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onboard NIC
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NIC built into the computer, usually on newer machines
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MAC (media access control) address
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a unique identifier each NIC has
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unshielded twisted pair (UTP)
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most connections are made using this, one of the two media connections
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optical fiber cables
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used if they carry alof of traffic or are far apart
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Ethernet also called IEEE.802.3 protocol
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worlds most popular protocol for LAN. specifies hardware characteristics such as which wire carries which signals.
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access point
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the WNIC operates according to the 802.11 protocal and connects to this.
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ISP three functions
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1.provides you with a legitimate internet address
2.serves as a gateway to the Internet 3.pays for the internet |
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Three times of ways to connect to ISP
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1. telephone line
2. DSL line 3. cable line |
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modem
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converts digital data into an analog (wavy symbol)
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PPP (Point-toPoint- Protocol)
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the way in which messages are packaged and handled between your modem and the ISP is governed by a protocol known as this (DIAL UP MODEMS)
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ADSL (Asymmetric Digital Subscriber Lines)
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DSL lines that have different upload and download speeds. Most homes and small businesses use this becuase they recieve more data than they transmit
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Symmetrical Digital Subscriber Lines (SDSL)
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some users and larger businesses need DSL lines that have the same recieving and transmitting speeds.
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narrowband
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transmissions with speeds less than 56 kbps (dial up)
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broadband
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speeds in excess of 2556 kbps. (DSL, CABLE)
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network od leased lines
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connects from diff geographical sites.
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(PSDN) public switched data network
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a network of computers and leased lines that is developed and maintained by a vendor that leases time on the network to other ogranizations
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(POP) point of presence
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each site in a PSDN must lease a line t connect to the PSDN and the location at which this occrus is called this
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Frame Relay
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can process traffic in the range of 56 kbps to 40Mbps. Slower than ATM but simpler and easier to handle
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Asynchronous transfer mode
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can process speeds from 1 to 156Mbps
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perimeter firewall
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sits outside the organizational networl; it is the first device that Internet traffic encounters
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Internal firewalls
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inside the organizational network
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packet-filtering firewall
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examines each part of a message and determines wheter to let that part pass
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(ACL) access control list
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encodes the rules stating which addresses are to be allowed and which are to be prohibited
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Virtual Private Network
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fourth WAN alternative which uses the Internet or a provate internet to create the appearance of private point-to-point connections
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tunnel
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a virtual private pathway over a public or shared network from the VPN client to the VPN server
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What is a computer network?
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a collection of computers that communicate with one another through transmission lines
Three basic types include: DSL DIAL UP CABLE |
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What are the components of a LAN
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computers connected on single company sites, usualy located within half a mile area.
components include switch, and (NIC) network interface card |
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What are the alternatives for a WAN?
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1. Internet Service Provider
-connection made through *regular phone lines * DSL line *Cable TV lines |
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How does encryption work?
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it transforms clear text into coded text by using a key which could by symmetric or asymmetric
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What is the purpose of a firewall?
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prevents unauthorized network access
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what is a VPN and why are the important
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Uses internet or provate network to create the ppearance of point-to-point connections. it is important becuase it enables secure, encrypted communications
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