单项选择题
A.The total end-to-end delay
B.The variations of delay.
C.The delay caused by placing the bits on the wire.
D.The time it takes for the bits to transit the physical media.
多项选择题 WhichtwostatementsregardingtheIS-ISDISelectionprocessaretrue？（）
单项选择题 WhichMQC-basedoutputqueueingmethodisdesignedtosupportmultipletrafficclassesincludingVoIPtraffic，mission-criticaltraffic，bulktraffic，interactivetrafficanddefaultclasstraffic？（）
单项选择题 WhatistheportnumberofanIPsecEncapsulatingSecurityPayloadpacket？（）