题目内容：
A.TrustboundariesareconfiguredinthecoreofthenetworktoprovidethemostefficientforwardingbaseduponQoSmarkings，B.SettingtrustboundariesattheedgeofthenetworkallowsintermediatehopdevicestoadministerQoSpolicieswithoutdetailedpacketidentification.
C.TrustboundariesareusedtodeterminewhichQoSmechanismwillbeappliedtothetraffic.
D.Atthetrustboundaries，theuntrustedtrafficwillbemarkedwithanewQoSvalueappropriateforthepolicyinplaceatthepointwherethetrafficenteredthecampusnetwork.
E.TrustboundariesdefinethefirewallrulesforQoSadmissionintoanetwork.
参考答案：