Before a queue group with a specific name may be created on a port or an IOM/IMM/XMA ingress forwarding plane, a queue group template with the same name must first be created. The template is used to define each queue, scheduling attributes, and its default parameters. When a queue or policer is defined in a queue group template, that queue exists in every instance of a port or forwarding plane queue group with that template name. The default queue or policer parameters (such as rate or mbs values) may be overridden with a specific value in each queue group. This works in a similar manner to SAP ingress or SAP egress QoS policies.
Queue sharing is also supported when the HSQ (IOM-4-HS) are used. On egress, it is possible to redirect forwarding classes from multiple SAPs to an HSQ queue group. The HSQ also uses the term queue group to describe a group of eight preconfigured hardware queues on its egress port. When queue sharing and redirection is configured on egress, a set of eight HSQ queues could be configured as a part of the queue group template. These correspond to eight hardware queues on the HSQ. When all eight egress fcs are mapped to the queue-group instantiated in the egress port, the per-sap HSQ queue-group resource is freed.