单项选择题
A.data marked with DSCP AF21，VOIP marked with DSCP EF
B.data marked with DSCP AF51，VOIP marked with DSCP EF
C.data marked with the DE-bit. VOIP marked with the CLP-bit
D.data marked with DSCP EF，VOIP marked with DSCP AF31
E.data marked with IP precedence 5，VOIP marked with DSCP EF
单项选择题 Anexpandingcompanyisdeployingleasedlinesbetweenitsmainsiteandtworemotesites.Thebandwidthoftheleasedlinesis128kb/seach，terminatedondifferentserialinterfacesonthemainrouter.TheselinksareusedforcombinedVOIPanddatatraffic.Thenetworkadministratorhasimplementeda VOIPsolutiontoreducecosts，andhasthereforereservedsufficientbandwidthinalowlatencyqueueoneachinterfacefortheVOIPtraffic.Usersnowcomplainaboutbadvoicequalityalthoughnodropsareobservedinthelowlatencyqueue.Whatactionwilllikelyfixthisproblem？（）
单项选择题 TheclassicSpanningTreeProtocol（802.1D1998）useswhichsequenceofvariablestodeterminethebestreceivedBPDU？（）
单项选择题 WhichofthesebestdescribestheactionstakenwhenaVTPmessageisreceivedonaswitchconfiguredwiththeVTPmode"transparent"？（）