Quality of Service
CiscoUCS providesthe followingmethods toimplement quality ofservice:
• System classes that specify the global configuration for certain types of trafficacross the entiresystem
• QoS policies that assign system classes for individual vNICs
• Flow control policies that determine how uplink Ethernet ports handle pause frames

System Classes

CiscoUCS uses DataCenter Ethernet (DCE) to handle alltraffic inside a Cisco UCS domain. This industry
standardenhancement to Ethernet divides the bandwidth of the Ethernet pipe into eight virtual lanes. Two
virtuallanes are reservedfor internalsystem andmanagement traffic. You can configure quality of service
forthe other six virtual lanes. System classes determinehow the DCE bandwidth in these six virtual lanes is
allocatedacross the entireCisco UCSdomain.
Eachsystem class reserves aspecific segment of thebandwidth for aspecific type of traffic.This provides a
levelof traffic management, even in an oversubscribed system. For example, you can configure the Fibre
ChannelPriority system class to determine the percentage of DCE bandwidth allocated to FCoE traffic.
Thefollowing table describes thesystem classes that you can configure:
Table 5: System Classes
DescriptionSystem Class
Aconfigurable set of system classes that you can include in the QoS policy
fora serviceprofile. Each system class manages one lane of traffic.
Allproperties ofthese systemclasses are availablefor you to assign custom
settingsand policies.
Platinum
Gold
Silver
Bronze
Asystem class that sets the quality of service for the lane reserved for Basic
Ethernettraffic.
Someproperties of this system class are preset and cannot be modified. For
example,this class has a drop policy that allows it to drop data packets if
required.You cannot disable this system class.
BestEffort
Asystem class that sets the quality of service for the lane reserved for Fibre
Channelover Ethernet traffic.
Someproperties of this system class are preset and cannot be modified. For
example,this class has a no-drop policy that ensures it never drops data packets.
Youcannot disable this system class.
FibreChannel
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Traffic Management