NCTI -HSD FINAL-DOJ 2 QUESTIONS WITH CORRECT ANSWERS 2025

NCTI -HSD FINAL-DOJ 2 QUESTIONS
WITH CORRECT ANSWERS 2025
TheWfirstWversionWofWtheWDataWOverWCableWServiceWInterfaceWSpecificationW(DOCSIS)WwasWapprovedWasWa
nWinternationalWstandardWbyWwhatWorganization?W-WCORRECTWANSWERW-
TheWInternationalWTelecommunicationWUnionW(ITU).



WhatWcriteriaWdoesWtheWDataWOverWCableWServiceWInterfaceWSpecificationW(DOCSIS)WcertificationWproces
sWensure?W-WCORRECTWANSWERW-
ComplianceWwithWtheWDOCSISWstandardWandWinteroperabilityWbetweenWsuppliers.



WhatWlayersWofWtheWOpenWSystemsWInterconnectionW(OSI)WreferenceWmodelWareWappliedWbetweenWData
WOverWCableWServiceWInterfaceWSpecificationW(DOCSIS)WmodemsWandWtheWcableWmodemWterminationWsys

temW(CMTS)?W-WCORRECTWANSWERW-
LayersW1WthroughW4W(PhysicalWlayer,WDataWLinkWLayer,WNetworkWLayer,WandWTransportWLayer)WareWapplied
WbetweenWtheWDOCSISWmodemWandWCMTS.




WhatWaccessWtechnologyWdoesWtheWfirstWversionWofWtheWDataWOverWCableWServiceWInterfaceWSpecificatio
nW(DOCSISW1.0)WuseWtoWsendWdataWupstreamWoverWtheWnetwork'sWRFWreturnWpath?W-
WCORRECTWANSWERW-TimeWdivisionWmultipleWaccessW(TDMA).




WhatWwasWaddedWtoWtheWfirstWDataWOverWCableWServiceWInterfaceWSpecificationW(DOCSIS)WthatWenabledW
broadbandWcableWoperatorsWtoWprovideWtelephoneWserviceWwithWqualityWandWreliabilityWthatWrivaledWthe
WproductsWofWtheWtraditionalWtelephoneWcompanies?W-WCORRECTWANSWERW-

QualityWofWserviceW(QoS)Wcontrols,WenhancedWsecurity,WandWadaptiveWequalizationWinWtheWupstreamWpat
h.



WhatWfeaturesWwereWintroducedWwithWtheW3.1WversionWofWtheWDataWOverWCableWServiceWInterfaceWSpeci
ficationW(DOCSISW3.1)WtoWincreaseWtheWdownstreamWandWupstreamWdataWthroughput?W-
WCORRECTWANSWERW-OrthogonalWfrequencyWdivisionWmultiplexingW(OFDM)WandWlow-densityWparity-

checkW(LDPC).



WhichWDataWOverWCableWServiceWInterfaceWSpecificationW(DOCSIS)WversionWwasWtheWfirstWtoWprovideWanW
optionWforWraisingWtheWtopWfrequencyWofWtheWupstreamWspectrumWtoW85WMHzWinWorderWtoWcreateWenou
ghWbandwidthWforWupstreamWcarriersWfromWmodemsWrunningWonWpreviousWDOCSISWversions?W-
WCORRECTWANSWERW-DOCSISW3.0.

, WhyWareWtheWdataWthroughputWratesWforWbothWdownstreamWandWupstreamWinWDataWOverWCableWService
WInterfaceWSpecificationW(DOCSIS)WnetworksWasymmetrical?W-WCORRECTWANSWERW-

BecauseWtheWnarrowerWbandwidthsWandWlowerWordersWofWmodulationWforWtheWreturnWpathWcarriersWcau
seWtheWDOCSISWdownstreamWandWupstreamWdataWratesWtoWbeWunequalWorWasymmetrical.



WhichWOpenWSystemsWInterconnectionW(OSI)WreferenceWmodelWlayersWdoesWtheWMACWLayerWinWtheWData
WOverWCableWServiceWInterfaceWSpecificationW(DOCSIS)Woverlap?W-WCORRECTWANSWERW-

TheWPhysicalWandWDataWLinkWLayers.



FromWwhereWdoWDataWOverWCableWServiceWInterfaceWSpecificationW(DOCSIS)WmodemsWreceiveWtheirWcon
figurationWfiles,WbillingWsystemWmessages,WandWaccessWcontrolWmessages?W-WCORRECTWANSWERW-
FromWtheWcableWmodemWterminationWsystemW(CMTS)WactingWasWaW"proxy"WorWmessengerWthatWtransfers
WmessagesWandWfilesWbetweenWtheWmodemsWandWtheWrespectiveWservers.




WhatWmessagesWmustWaWcableWmodemWreceiveWfromWtheWdownstreamWsignalWinWorderWtoWbeginWaWtran
smittingWrelationshipWwithWtheWcableWmodemWterminationWsystemW(CMTS)?W-WCORRECTWANSWERW-
AnWupstreamWchannelWdescriptorW(UCD)Wmessage,WaWsymbolWtimingWmessageW(SYNC),WandWaWbandwidt
hWallocationWmessageW(MAP).



WhatWinstructionsWmightWaWcableWmodemWterminationWsystemW(CMTS)WsendWinWaWRNG-
RSPWmessageWtoWmodifyWtheWmodem'sWtransmissionWparameters?W-WCORRECTWANSWERW-
AnWadjustmentWtoWtheWmodem'sWtimingWinterval,WtransmitWfrequency,WorWpowerWlevel



WhyWwouldWaWcableWoperatorWconsiderWactivatingWdeviceWclassWidentificationW(DCI)WasWpartWofWaWDOCSI
SWmodem'sWinitialization?W-WCORRECTWANSWERW-
ToWenableWtheWcableWoperatorWtoWdefineWspecialWmodemWclassesWorWserviceWlevelsWthatWcanWbeWprioriti
zedWforWrangingWafterWaWmassiveWoutage.



WhatWdoesWaWDOCSISW3.1WseekWfirstWwhenWsynchronizingWwithWtheWcableWmodemWterminationWsystemW
(CMTS)WinWorderWtoWreceiveWoperationalWinformation?W-WCORRECTWANSWERW-
AnWorthogonalWfrequencyWdivisionWmultiplexingW(OFDM)WchannelWthatWcontainsWaWsetWofWcontiguousWsu
bcarriersWcalledWtheWPHYWlinkWchannelW(PLC).