Multitech MVP 800 Specifikace stáhnout pdf (Strana 115)

 Chapter6—UsingtheSoftware

MultiVOIP®Voice/FaxoverIPGateways 115

IPStatistics



UDPversusTCP.(UserDatagramProtocolversusTransmissionControlProtocol).UDPprovidesunguaranteed,

connectionlesstransmissionofdataacrossanIPnetwork.Bycontrast,TCPprovidesreliable,connection‐

orientedtransmissionofdata.

BothTCPandUDPsplitdataintopacketscalled“datagrams.”However,TCPincludesextraheadersinthe

datagramto

enableretransmissionoflostpacketsandreassemblyofpacketsintotheircorrectorder ifthey

arriveoutoforder.UDPdoesnotprovidethis.LostUDPpacketsareirretrievable;thatis,out‐of‐orderUDP

packetscannotbereconstitutedintheirproperorder.

Despitethesedisadvantages,UDPpacketscanbe

transmittedfasterthanTCPpackets—asmuchasthreetimes

faster.Incertainapplications,likeaudioandvideodatatransmission,theneedforhighspeedoutweighsthe

needforverifieddataintegrity.Soundorpicturesoftenremainintelligibledespiteacertainamountoflostor

disordereddatapackets(whichcomesthrough as

static).

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Multitech MVP 800 Specifikace Strana 115