TheInternetisbasedonconnectionlessend-to-endpacketservice,whichtraditionallyprovidedbest-effortmeansofdata(请作答此空)usingtheTransmissionControlProtocol/InternetProtocolSuite.Althoughthe()designgivestheInternetitsflexibilityandrobustness,itspacketdynamicsalsomakeitpronetocongestionproblems,especiallyat()thatconnectnetworksofwidelydifferentbandwidths.TheinitialQoSfunctionsetwasforinternethosts.Onemajorproblemwithexpensivewide-area()linksistheexcessiveoverheadduetosmallTransmissionControlProtocolpacketscreatedbyapplicationssuchastelnetandrlogin.TheNagle()，whichsolvesthisissue,isnowsupportedbyallIPhostimplementations.
A.transformation B.transportation C.processing D.progressing正确答案B
