When ingress access port queue groups are configured, hardware queues are allocated to each switch fabric destination for each queue configured in the queue group template.
The allocation of ingress access port queue group hardware queues has been optimized for the 7950 XRS-20 systems to avoid allocating ingress hardware queues to XCMs in slots 11 and above.
When the first XCM in slot 11 or above is provisioned, additional ingress hardware queues are allocated to XCMs in slots 11 to 20 for any configured ingress access port queue group queue. If sufficient hardware queues are unavailable, the XCM provisioning fails. Adding queues to the queue group template or adding additional ingress access port queue groups continues to require more hardware queue to be allocated, with the configurations failing if there are not sufficient available. When the last XCM in slot 11 and above is unprovisioned, the related additional hardware queues to all of the XCMs in slots 11 and above are freed.