Cisco Nexus 5000 Series Configuration Manual page 19

Configuring QoS
• Type queuing—A type queuing policy is used to define the scheduling characteristics of the queues
associated with system classes.
• Type qos—A type qos policy is used to classify traffic that is based on various Layer 2, Layer 3, and
Layer 4 fields in the frame and to map it to system classes.
OL-20921-01
An additional parameter pfc-cos can be configured. This parameter identifies the class of
service (CoS) values to assert priority flow control (PFC) when traffic for a no-drop system
class is not mapped based purely on CoS experiences congestion.
◦Queue Limit—This configuration specifies the number of buffers that need to be reserved to
the queues of this system class. This option is not configurable for no-drop system classes.
◦Set CoS value—This configuration is used to mark 802.1p values for all traffic mapped to
this system class. For the Cisco Nexus 5020 switch and the Cisco Nexus 5010 switch, the
marking value for a system class needs to be unique and cannot be used as a marking value
for any other system class. The marking value does not need to be unique for the Cisco Nexus
5548 switch.
Note Some configuration parameters when applied to an EtherChannel are not reflected on
the configuration of the member ports.
◦Classification—The traffic that matches this class are as follows:
◦QoS Group—A class-map of type queuing identifies a system-class and is matched by its
associated qos-group.
◦Policy—The actions that are performed on the matching traffic are as follows:
These policies can be attached to the system qos target or to any interface. The output
Note
queueing policy is used to configure output queues on the switch associated with system
classes. The input queuing policy is used to configure scheduling for queues in the CNA.
The input queuing policy parameters are signalled to the CNA over the DCBX protocol.
◦Bandwidth—Sets the guaranteed scheduling deficit weighted round robin (DWRR) percentage
for the system class.
◦Priority—Sets a system class for strict-priority scheduling. Only one system class can be
configured for priority in a given queuing policy.
Some configuration parameters when applied to an EtherChannel are not reflected on
Note
the configuration of the member ports.
◦Classification—The traffic that matches this class are as follows:
◦Access Control Lists—Classifies traffic based on the criteria in existing ACLs.
Cisco Nexus 5000 Series NX-OS Quality of Service Configuration Guide
Policy Types
9