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- Microsoft Press Microsoft Encyclopedia of Security
- Wen Chu Chen, Grace J. Yoo Encyclopedia of Asian American Issues Today (2 volumes) (2009)
- QoS in Integrated 3G Networks Robert Lloyd Evans (2)
- Cisco CCIE Fundamentals Network Design
- Cisco Ccie Fundamental Network Design An
- Swieci W Dziejach Narodu Polski
- Porożyńska Iwona MiłoÂść kocha czary
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- Robinson Kim Stanley Czerwony Mars (2)
- Moorcock Michael Zwiastun Burzy Sagi o Elryku Tom VIII
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.basis for the switching.tBroadcast: Transmitted to any station oruparty capable of receiving, rather thanto a specific receiver.A radio transmis-vsion is broadcast.wxyz 242 Data CompressionCOMMON DATA COMMON DATA TRANSMISSIONTRANSMISSION SCHEMES SCHEMES (CONTINUED)Compression BasesThe basis for the compression can be anyof the following:Patterns in bit sequences, as in run-length limited (RLL) encodingPatterns of occurrences of particularData Compressionbyte values, as in Huffman or LZWencodingData compression is a method of reducingthe amount of data used to represent theCommonly occurring words ororiginal information.This can be accom-phrases, as in the use of abbreviationsplished by eliminating redundancy.or acronyms Data Encryption Key (DEK) 243aCOMMON DATA TRANSMISSION SCHEMES (CONTINUED)bcdefghijklmnopqrattain compression ratios of 100:1 and evenCompression Methodshigher.sThe two types of compression methods arelossless and lossy.In lossless compression,tData Encryption Algorithm (DEA)all the original information can be recov-ered.Lossless methods generally compress uSEEdata to about 50 or 33 percent of the origi-DEA (Data Encryption Algorithm)vnal size.These values represent compressionratios of 2:1 and 3:1, respectively.LosslesswData Encryption Key (DEK)compression methods rarely reach ratiosxhigher than 5:1 or so.SEEIn lossy compression, some of the originalDEK (Data Encryption Key)yinformation will be lost.Lossy methods canz 244 Data-Flow Controlinclude UDP (User Datagram Protocol) inData-Flow Controlthe Internet s TCP/IP protocol suite, CLNP(Connectionless Network Protocol) in theThe fifth layer in IBM s SNA.OSI Reference Model, and DDP (DatagramSEEDelivery Protocol) in the AppleTalk protocolSNA (Systems Network Architecture)suite.SEE ALSOData ForkConnectionless Service; Connection-The data fork is the data portion of a Mac-Oriented Serviceintosh file.It is the part of a Macintosh filethat is transferred to non-Macintosh envi-Datakit VCSronments, such as DOS or UNIX.A data-switch product from AT&T.DatakitSEE ALSOVCS offers communications channels rang-Macintoshing from 9.6 kilobits per second to 8 mega-bits per second, and can be linked to X.25networks.DatagramA datagram is a packet that includes bothData Linksource and destination addresses providedby the user, rather than by the network.AIn communications, the components anddatagram can also contain data.A messagemedium necessary for communicationmight be sent as multiple datagrams, whichbetween two stations or parties.Themay be delivered to the destination in non-medium is generally (but not necessarily)consecutive order.Receipt of a datagram isa wire or fiber-optic cable, and the compo-not acknowledged.nents are the transmitting and receivingDatagram routing takes place at the net-facilities at either end of the link.work layer of the OSI Reference Model.Datagram transmission takes place at theData-Link Connection Identifierdata-link layer.(DLCI)Datagram services are provided inconnectionless (as opposed to connection-SEEoriented) transmissions.Because connection-DLCI (Data-Link Connection Identifier)less transmissions do not necessarily deliverdatagrams in order, datagram services can-Data-Link Control (DLC)not guarantee successful message delivery.Receipt verification is the responsibility of aSEEhigher-level protocol, which must be able toDLC (Data-Link Control)assemble the message from the datagrams.Protocols that provide this type of service Data Protection 245(MHz) bandwidth in the 140 MHz rangeaData Network Identification Codebetween 1.85 and 1.99 gigahertz (AHz).(DNIC)The bandwidth is to be used for wirelessbcommunications using radio waves.Trans-SEEcmissions within the allocated bandwidthDNIC (Data Network Identificationcould have a maximum power of 1 watt.Code)dThis maximum is strong enough for a 50meter (165 feet) transmission range, buteData Over Voice (DOV)weak enough to allow multiple wirelessfnetworks to operate in different parts ofIn communications, a strategy for transmit-the spectrum without interference.ting data over the voice channel at the samegtime as a voice transmission.A human lis-BROADER CATEGORYhtener would not hear the data being trans-Transmission, Wirelessmitted.DOV requires special equipment.iSEE ALSOData ProtectionjDUV (Data Under Voice)Data protection involves the safeguarding ofkdata being transmitted across the networkData Packetor stored somewhere on the network.lVarious steps can be taken to protect net-In general, a data packet is a well-definedmwork data.Most of the measures costblock that contains user or application data
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