Queuing

QoS queuing configuration (type queuing) controls egress scheduling on NX-OS devices. Queuing policy maps reference the system-defined queuing classes (for example c-out-q1 to c-out-q-default) and assign strict priority levels, bandwidth and remaining bandwidth percentages, minimum/maximum shaping rates, queue limits and congestion avoidance (WRED/ECN random-detect or Approximate Fair Discard afd) to each queue. A queuing policy can be applied system-wide as the output service policy, with optional statistics collection. Traffic is mapped to queues based on the QoS groups set by QoS classification policies.

Diagram

Classes

nxos

Name	Type	Constraint	Mandatory	Default Value
devices	List	devices	No
device_groups	List	device_groups	No
global	Class	global	No
templates	List	templates	No

devices (nxos)

Name	Type	Constraint	Mandatory	Default Value
configuration	Class	configuration	No

device_groups (nxos)

Name	Type	Constraint	Mandatory	Default Value
configuration	Class	configuration	No

global (nxos)

Name	Type	Constraint	Mandatory	Default Value
configuration	Class	configuration	No

templates (nxos)

Name	Type	Constraint	Mandatory	Default Value
configuration	Class	configuration	No

configuration (nxos.devices)

Name	Type	Constraint	Mandatory	Default Value
qos	Class	qos	No

qos (nxos.devices.configuration)

Name	Type	Constraint	Mandatory	Default Value
queuing_policy_maps	List	queuing_policy_maps	No
system_service_policy_queuing_output	String		No
system_service_policy_queuing_output_statistics	Boolean	true, false	No

queuing_policy_maps (nxos.devices.configuration.qos)

Name	Type	Constraint	Mandatory	Default Value
name	String		Yes
match_type	Choice	match-any, match-all, match-first	No
classes	List	classes	No

classes (nxos.devices.configuration.qos.queuing_policy_maps)

Name	Type	Constraint	Mandatory	Default Value
name	String		Yes
priority_level	Integer	min: 1, max: 8	No
bandwidth_percent	Integer	min: 0, max: 100	No
bandwidth_remaining_percent	Integer	min: 0, max: 100	No
shape_min	Integer	min: 0, max: 400000000000	No
shape_min_unit	Choice	bps, kbps, mbps, gbps, pps, percent	No
shape_max	Integer	min: 0, max: 400000000000	No
shape_max_unit	Choice	bps, kbps, mbps, gbps, pps, percent	No
queue_limit	Integer	min: 0, max: 12582913	No
queue_limit_unit	Choice	bytes, kbytes, mbytes	No
queue_limit_dynamic	Integer	min: 0, max: 10	No
random_detect	Class	random_detect	No
afd	Class	afd	No

random_detect (nxos.devices.configuration.qos.queuing_policy_maps.classes)

Name	Type	Constraint	Mandatory	Default Value
minimum_threshold	Integer	min: 0, max: 52428800	No
minimum_threshold_unit	Choice	packets, bytes, kbytes, mbytes	No
maximum_threshold	Integer	min: 0, max: 52428800	No
maximum_threshold_unit	Choice	packets, bytes, kbytes, mbytes	No
drop_probability	Integer	min: 0, max: 100	No
weight	Integer	min: 0, max: 15	No
cap_average	Boolean	true, false	No
threshold	Choice	burst-optimized, mesh-optimized	No
ecn	Boolean	true, false	No

afd (nxos.devices.configuration.qos.queuing_policy_maps.classes)

Name	Type	Constraint	Mandatory	Default Value
queue_desired	Integer	min: 1, max: 52428800	No
queue_desired_unit	Choice	bytes, kbytes, mbytes	No
ecn	Boolean	true, false	No

Examples

Example 1: Egress queuing policy with priority and bandwidth remaining allocation, applied system-wide

nxos:
  devices:
    - name: SPINE1
      configuration:
        qos:
          system_service_policy_queuing_output: QM-FABRIC-EGRESS
          system_service_policy_queuing_output_statistics: true
          queuing_policy_maps:
            - name: QM-FABRIC-EGRESS
              match_type: match-first
              classes:
                - name: c-out-q1
                  priority_level: 1
                - name: c-out-q2
                  bandwidth_remaining_percent: 30
                - name: c-out-q-default
                  bandwidth_remaining_percent: 70

Example 2: Egress queuing policy with WRED/ECN congestion avoidance

nxos:
  devices:
    - name: LEAF1
      configuration:
        qos:
          system_service_policy_queuing_output: QM-WRED-EGRESS
          queuing_policy_maps:
            - name: QM-WRED-EGRESS
              classes:
                - name: c-out-q1
                  priority_level: 1
                - name: c-out-q2
                  bandwidth_remaining_percent: 50
                  random_detect:
                    minimum_threshold: 150
                    minimum_threshold_unit: kbytes
                    maximum_threshold: 3000
                    maximum_threshold_unit: kbytes
                    drop_probability: 7
                    weight: 5
                    cap_average: true
                    ecn: true
                - name: c-out-q-default
                  bandwidth_remaining_percent: 50
                  random_detect:
                    threshold: mesh-optimized
                    ecn: true

Example 3: Egress queuing policy applied to individual Ethernet and port-channel interfaces

nxos:
  devices:
    - name: LEAF1
      configuration:
        qos:
          queuing_policy_maps:
            - name: QM-UPLINK-EGRESS
              classes:
                - name: c-out-q3
                  priority_level: 1
                - name: c-out-q2
                  bandwidth_remaining_percent: 40
                - name: c-out-q1
                  bandwidth_remaining_percent: 30
                - name: c-out-q-default
                  bandwidth_remaining_percent: 30
        interfaces:
          ethernets:
            - id: 1/49
              service_policy_type_queuing_output: QM-UPLINK-EGRESS
              service_policy_type_queuing_output_statistics: true
          port_channels:
            - id: 10
              service_policy_type_queuing_output: QM-UPLINK-EGRESS

Example 4: Egress queuing policy with guaranteed bandwidth, shaping and queue limits

nxos:
  devices:
    - name: LEAF1
      configuration:
        qos:
          system_service_policy_queuing_output: QM-SHAPED-EGRESS
          queuing_policy_maps:
            - name: QM-SHAPED-EGRESS
              classes:
                - name: c-out-q1
                  bandwidth_percent: 20
                  shape_min: 1000
                  shape_min_unit: mbps
                  shape_max: 2000
                  shape_max_unit: mbps
                  queue_limit: 1000
                  queue_limit_unit: kbytes
                - name: c-out-q-default
                  bandwidth_percent: 80
                  queue_limit_dynamic: 5