说明案例文案bcmsn30s07l02.pptx

ConfiguringCampusSwitchestoSupportVoicemodatingVoiceTrafficonCampusSwitches

QoSandVoiceTrafficintheCampusModel

LAN-BasedClassificationandMarking

Layer2Marking:802.1p,CoS802.1pUserPriorityfieldisalsocalledclassofservice(CoS).DifferenttypesoftrafficareassigneddifferentCoSvalues.CoS6and7arereservedfornetworkuse.

Layer3Marking:

IPPrecedence,DSCPIPv4ThreemostsignificantbitsofToSbytearecalledIPprecedence.Otherbitsareunused.DiffServSixmostsignificantbitsofToSbytearecalledDiffServCodePoint(DSCP).DSCPisbackwardcompatiblewithIPprecedence.Remainingtwobitsareusedforflowcontrol.

ClassificationTools:TrustBoundariesAdeviceis“trusted”ifitcorrectlyclassifiespackets.Forscalability,classificationshouldbedoneasclosetotheedgeaspossible.Theoutermosttrusteddevicesrepresentthe

“trustboundary.”andareoptimal;isacceptable(iftheaccessswitchcannotperformclassification).123

ConfiguringaSwitchforAttachmentofaCiscoIPPhoneVoicetraffictaggedforvoiceVLANDataVLANtrafficfromPCcanbeUntrustedTrustedSettoaspecificvalue

BasicSwitchCommandstoSupportAttachmentofaCiscoIPPhoneConfigurevoiceVLANswitchportvoicevlan110ConfiguretrustandCoSoptionsmlsqostrustcosmlsqostrustdevicecisco-phonemlsqosextendtrustswitchportpriorityextendcoscos_valueVerifyconfigurationshowinterfacesfa0/4switchportshowmlsqosinterfacefa0/4

ConfigurationExampleSwitch(config)#mlsqosSwitch(config)#interfacefastethernet0/4

Switch(config-if)#switchportvoicevlan110Switch(config-if)#switchportaccessvlan10Switch(config-if)#mlsqostrustcos

Switch(config-if)#mlsqostrustdevicecisco-phone

Switch(config-if)#ctrl-Z

Switch#showinterfacesfastethernet0/4

Switch#showmlsqosinterfacefastethernet0/4

FastEthernet0/4

truststate:trustcos

trustmode:trustcos

COSoverride:dis

defaultCOS:0

pass-through:none

tr