Specifications

Quality of Service Overview
May 09, 2011 Page 6 of 38
resourcereferenceconfiguredinCoSsettings,andtheactualTxQorrateli mitingportresourcefor
thismapping.
Port Group and Type
CoSportgroupsprovideforgroupingportsbyCoSfeatureconfigurationandporttype.Portsare
requiredtobeconfiguredbygroups:thisfeatureprovidesameaningfulwayofidentifyingports
bysimilarfunctionalityandporttype.
Groupsconsistofagroupnumberandporttypeandarenumberedassuch,
port‐group.port‐type.
Theportgroupnumberisconfigurable.Theporttypeisfixedbasedupontheportmodule.Aport
onanS‐Seriesmoduleisalwaysporttype1.
Forexample:portgroup0,porttype0wouldbenumberedportgroup0.0.Adefaultportgroup
existsperhardwareresource:TxQ,IRL,ORL,andfloodcontrol.Thedefaultportgroupis
identifiedasportgroup0andporttype0or1andareindexedas0.0or0.1foreachfeature.These
defaultportgroupscannotberemovedandallphysicalportsinthesystemare
assignedtooneof
thetwoportgroupsforeachfeature.
Additionalportgroups,uptoeleventotal,maybecreatedbychangingtheportgroupvalue.Ports
assignedtoanewportgroupcannotbelongtoanothernon‐defaultportgroupentryandmustbe
comprisedofthesameport
typeasdefinedbytheportgroupyouareassociatingitwith.The
creationofadditionalportgroupscouldbeusedtocombinesimilarportsbytheirfunctionfor
flexibility.Forinstance,portsassociatedwithuserscanbeaddedtoaportgroupcalledUsersand
portsassociatedwithuplink
portscanbeaddedtoaportgroupcalled Uplink.Usingtheseport
groups,aclassofserviceuniquetoeachgroupcanassigndifferentratelimitstoeachportgroup.
UserportscanbeassignedaratelimitconfiguredinoneCoS,whileUplinkportscanbeassigned
adifferent
ratelimitconfiguredinanotherCoS.Amaximumof8configurableTxQsperCoSare
supported.
PortTypeisafixedvaluethatdeterminestheTxQ,IRL,ORL,andfloodcontrolresource
capabilitiesbaseduponthemoduletheportbelongsto.Knowledgeofthesecapabilitiesis
importantwhenconfiguringqueuebehaviors.
SeeCoSPortTypeonpage 28foralistingofport
typesbyplatform.
CoSporttypecanbedeterminedusingtheshowcosport‐typecommand.
CoS Settings Reference to Port Resource Mapping
UsetheCoSreferenceconfigurationtomaptheresourcereferencefromtheCoSsettings
configurationtotheporthardwareresourcesbeingacteduponbythisconfiguration.
•TxQCoSreference–MapstheCoSsettingsTxQ referencetothequeuetheCoSsettings
referenceisbeingremappedto.Forexample,ifthe
CoSsettingsTxQreferenceissetto8and
thequeueforthisconfigurationissetto9,hardwareresourcequeue8isremappedtoqueue9
forthisCoSconfiguration.
•IRLCoSreference–MapstheCoSsettingsIRLreferencetothe IRLportresourcetheratelimit
isto
beappliedto.
•ORLCoSreference–MapstheCoSsettingsORLreferencetotheORLportresourcetherate
limitistobeappliedto.
Note: Only non-low latency queues are configurable for CoS port group. Which queues are Low
Latency Queues (LLQ) depends upon the hardware. LLQs are labeled LLQ in the show cos
port-config command display.