题目内容:
A.TrustboundariesarepointsinthenetworkwhereLayer2CoSmarkingsareconvertedtoLayer3DSCPorIPprecedencemarkings.B.TrustboundariesareapointinthenetworkwhereQoSfunctionalitybeginsandends.
C.Trustboundariesdeterminewhethercertaintypesoftrafficcanpass.
D.TrustboundariesareapointinthenetworkwheredecisionsaboutCoSmarkingsonincomingpacketsaremade.
E.Noneoftheotheralternativesapply
参考答案: