The Policy tab allows you to configure transmit queues as a component of a class of service (CoS).
There are two transmit queue configuration capabilities:
- Transmit Queue Configuration — Allows you to set the transmit queue associated with the class of service.
- TxQ Shaper — Transmit Queue Rate Shapers let you pace the rate at which traffic is transmitted out of a transmit queue.
These two capabilities are configured in the Class of Service tab available from the Policy tab.
For more information, see the section on transmit queues in Getting Started with Class of Service.
Instructions on:
Transmit Queue Configuration
Transmit queues represent the hardware resources for each port used in scheduling packets for egressing the device. By default, the static classes of service 0-7 map to transmit queues 0-7. The actual transmit queue number can vary depending on the number of queues supported by the port.
The Priority column in the Class of Service Configuration window displays the actual transmit queues associated with the class of service for each port type. Double-click in the column to see a drop-down list where you can select a new transmit queue for all port types, or select a different transmit queue for each individual port type.
| TIP: | For more detailed information, refer to the tooltip that displays when you hover the cursor over the Queue column. |
Transmit Queue Rate Shapers
Rate shapers let you pace the rate at which traffic is transmitted out of a transmit queue. Packets received above the configured rate are buffered rather than dropped. Only when the buffer fills are packets dropped.
The following steps describe how to configure rate shapers in the Policy tab:
- In the Class of Service left-panel tab, select the class of service where you want to configure the transmit queue.
- Select the Edit button beside the Transmit Queue field and select the desired Transmit Queue from the drop-down list.
- Select Open/Manage Domain > Save Domain to save the configuration change to the database.
For more information, see the section on transmit queues in Getting Started with Class of Service.
| NOTE: | A rate shaper is associated to a specific transmit queue, not a CoS. This means that the 1) you should select the queue you want to use for a CoS first, then set the shaper and 2) all CoS using that queue uses the same rate shaper. Associating a rate shaper to a transmit queue is accomplished via the CoS - Transmit Queue Mappings tab. For additional information, see the CoS - Transmit Queue Mappings Tab (Transmit Queue Port Group) Help topic. |
For information on related help topics: