qos priority-to-pg

Configures priority-to-priority-group (PG) mapping for priority flow control (PFC).
Syntax
qos priority-to-pg qosp0 priority-PG-map qosp1 priority-PG-map qosp2 priority-PG-map qosp3 priority-PG-map qosp4 priority-PG-map qosp5 priority-PG-map qosp6 priority-PG-map qosp7 priority-PG-map
no qos priority-to-pg
Command Default

Priority-to-PG mapping is not configured.

Parameters
qosp0 through qosp7
Configures the internal priority based on classification in the range 0 through 7.
priority-PG-map
Specifies the internal priority-to-PG mapping. The range is from 0 through 3.
Modes

Global configuration mode

Usage Guidelines

This command is not supported for RUCKUS ICX 8200, ICX 7150, or ICX 7650 devices.

You must configure the priority-flow-control enable command to enable PFC globally before you configure priority-to-PG mapping.

Note: Default mapping, mapping priorities, and mapping restrictions changed in FastIron Release 08.0.20. The following restrictions apply:

  • Priority 7, and only Priority 7, is always mapped to PG4.
  • PG4 is always lossy.
  • PFC cannot be enabled on PG4.
  • Priorities 0 through 5 can be mapped to PG0, PG1, and PG2. They cannot be mapped to PG3 or PG4.

The default values of priority-to-PG maps:

  • QoS internal priority 0 is mapped to PG 0
  • QoS internal priority 1 is mapped to PG 0
  • QoS internal priority 2 is mapped to PG 1
  • QoS internal priority 3 is mapped to PG 1
  • QoS internal priority 4 is mapped to PG 1
  • QoS internal priority 5 is mapped to PG 2
  • QoS internal priority 6 is mapped to PG 2
  • QoS internal priority 7 is mapped to PG 4

The default values of priority-to-PG maps in releases prior to Release 08.0.20:

  • QoS internal priority 0 is mapped to PG 0
  • QoS internal priority 1 is mapped to PG 0
  • QoS internal priority 2 is mapped to PG 1
  • QoS internal priority 3 is mapped to PG 1
  • QoS internal priority 4 is mapped to PG 1
  • QoS internal priority 5 is mapped to PG 2
  • QoS internal priority 6 is mapped to PG 2
  • QoS internal priority 7 is mapped to PG 2

In releases prior to Release 08.0.20, you can map QoS internal priority 7 to PG 3. You can also map any other priority to PG 3 if it meets the following requirements:

  • Lower priorities are mapped to lower PGs.
  • PGs are configured in ascending order.
  • Multiple priorities in a single PG must be consecutive.

Priority-to-PG mapping is not configurable in other modes. Symmetrical and asymmetrical 802.3x flow control modes have their own default priority-to-PG mapping.

You must configure PGs in ascending order, 0 to 3. You can configure a higher-order PG only if all the lower-order PGs have some mapped priorities.

The no form of the command restores the default priority-to-PG map.

Examples

The following example configures a priority-to-PG map. 

device# configure terminal
device(config)# priority-flow-control enable
device(config)# qos priority-to-pg qosp0 0 qosp1 1 qosp2 1 qosp3 1 qosp4 2 qosp5 2 qosp6 2 qosp7 4

The following example restores the default priority-to-PG map. 

device# configure terminal
device(config)# no qos priority-to-pg qosp0 0 qosp1 1 qosp2 1 qosp3 1 qosp4 2 qosp5 2 qosp6 2 qosp7 4
History
Release version Command history
08.0.10 This command was introduced.
08.0.20 This command was modified to change priority 7-to-PG4 mapping and mapping restrictions for priorities 0 through 5.

Related commands:

priority-flow-control enable
Parent topic: Commands O, P, Q, R, and Sa through Sh