On Trident and Trident+ based switches, known unicast packets can be assigned to a specific queue between queues from 0 to 7, while unknown unicast packets, multicast packets, and broadcast packets can be assigned to a specific queue between queues from 0 to 3.
Configure a Scheduler
A scheduler, which determines the QoS working mode and weight, should be configured first when you configure QoS. The working mode can be SP, WRR, or WFQ, and the weight is 1 to 15.
SP is strictly a priority queue. When two PCs send 100% traffic to a same PC, all packets from the lower priority PC will be discarded. The default working mode is SP.
WRR is a weighted round robin queue, and under this mode, user can configure weight. If PCA and PCB sends 100% traffic to the same PCC, the PCC will receive packets from PCA and PCB according to the weight proportion in the corresponding queue.
WFQ is weighted fair queuing. Under this mode, user can configure guaranteed-rate and weight, and the guarantee is only available in WFQ mode. If PCA and PCB send 100% traffic to the same PCC, the PCC will receive packets from PCA and PCB according to the weight proportion and the guaranteed-rate in the corresponding queue.
Configure a Forwarding Class
A forwarding class, which determines the queue number of the specified traffic type, should be configured after the scheduler when configuring QoS. The effective local-priority is 0 to 7.
Configure Scheduler Profile
Scheduler profile, which defines a queue used as a kind of scheduler on egress port, is the map of a forwarding class and a scheduler.
Configure Scheduler Profile to Specified Port
Scheduler profile should be configured to egress port. It only applies to egress packet. Ingress packet is invalid.
Configure a Classifier with IEEE 802.1/DSCP/ToS
A classifier should be configured first, which is used to specify the associated forwarding class. User can select a classifier trust mode, such as IEEE 802.1, DSCP, or ToS, according to need. It decides the priority trust model. Configure trust mode IEEE 802.1 as follows:
Configure Classifier Relevant to Forwarding Class
After configuring a classifier trust mode, user can configure the classifier relevant to the specified forwarding class. Code point and scheduler should be configured at the same time. The code-point is matched with the forwarding class local-priority, meaning that when the flow matches the specified code point, the flow will enter the specified queue. When the classifier trust mode is IEEE 802.1 or ToS, the code point is 0 to 7. When the classifier trust mode is dscp, the code point is 0 to 63.
Configure Classifier to Specified Port
After configuring as above, the classifier should be applied to specified ports. It determines the port priority trust model, data stream and queue matching rules, scheduling model, weight, and guaranteed-rate. When the classifier configures the scheduler, the classifier should be used in the egress port. When the classifier configures code point, the classifier should be used in ingress port.