WhicharethreeadvantagesofPPPoAimplementation?() A.NAPandNSPprovidesecureaccesstocorporategatewayswithoutmanagingend-to-endPVCs.NAPandNSPuseLayer3routing，Layer2Forwarding，orLayer2TunnelingProtocoltunnels.Hence，theycanscaletheirbusinessmodelsforsellingwholesaleserviceB.TheNSPcanoversubscribebydeployingidleandsessiontimeoutsusinganindustrystandard RADIUSserverforeachsubscriberC.OnlyasinglesessionperCPEononevirtualchannel （VC).Theusernameandpasswordare configuredontheCPE，soallusersbehindtheCPEforthatparticularVCcanaccessonlyonesetofservices.Userscannotselectdifferentsetsofservices，althoughusingmultipleVCsandestablishing differentPPPsessionondifferentVCsispossibleD.IfasingleIPaddressisprovidedtotheCPE，andNATorPATisimplemented，certain applications suchasIPTV，whichembedIPinformationinthepayload，wellnotwork.Additionally，ifanIP subnet featureisused，anIPaddressalsohastobereservedfortheCPEE.PPPoAcanusethefeaturesontheCiscoServiceSelectionGateway（SSG）
A.NAPandNSPprovidesecureaccesstocorporategatewayswithoutmanagingend-to-endPVCs.NAPandNSPuseLayer3routing，Layer2Forwarding，orLayer2TunnelingProtocoltunnels.Hence，theycanscaletheirbusinessmodelsforsellingwholesaleservice
B.TheNSPcanoversubscribebydeployingidleandsessiontimeoutsusinganindustrystandard RADIUSserverforeachsubscriber
C.OnlyasinglesessionperCPEononevirtualchannel （VC).Theusernameandpasswordare configuredontheCPE，soallusersbehindtheCPEforthatparticularVCcanaccessonlyonesetofservices.Userscannotselectdifferentsetsofservices，althoughusingmultipleVCsandestablishing differentPPPsessionondifferentVCsispossible
D.IfasingleIPaddressisprovidedtotheCPE，andNATorPATisimplemented，certain applications suchasIPTV，whichembedIPinformationinthepayload，wellnotwork.Additionally，ifanIP subnet featureisused，anIPaddressalsohastobereservedfortheCPE
E.PPPoAcanusethefeaturesontheCiscoServiceSelectionGateway（SSG）