Dell PowerConnect FCS624S Configuration Guide - Page 645

17 Scheduling Hardware Queue Weighted Round Robin (WRR) mode 3 Weight 82% 2 Weight 6% 1 Weight 6% 0 Weight 6% Hybrid WRR and SP Strict Priority Weight 40% Weight 30% Weight 30% Strict Priority (SP) mode Strict Priority Strict Priority Strict Priority Strict Priority The example configuration described below is for a default, non-jumbo mode. The hardware queues for WRR mode is calculated as follows. Front end queue 3= 75%+7% = 82% Front end queue 2 = 3%+3% = 6% Front end queue 1 = 3%+3% = 6% Front end queue 0 = 3%+3% = 6% The hardware queues for Hybrid WRR and SP mode is calculated as follows. Front end queue 3 is strict priority Front end queue 2 = 25%+15% = 40% Front end queue 1 = 15%+15% = 30% Front end queue 0 = 15%+15% = 30% Scheduling Scheduling is the process of mapping a packet to an internal forwarding queue based on its QoS information, and servicing the queues according to a mechanism. QoS queuing methods The following QoS queuing methods are supported in all IronWare releases for the PowerConnect devices: • Weighted round robin (WRR) - WRR ensures that all queues are serviced during each cycle. A WRR algorithm is used to rotate service among the eight queues on the PowerConnect devices. The rotation is based on the weights you assign to each queue. This method rotates service among the queues, forwarding a specific number of packets in one queue before moving on to the next one. NOTE In stacking mode, the qosp7 queue is reserved as strict priority (SP) under weighted queuing. Attempts to change the qosp7 setting will be ignored. WRR is the default queuing method and uses a default set of queue weights. The number of packets serviced during each visit to a queue depends on the percentages you configure for the queues. The software automatically converts the percentages you specify into weights for the queues. PowerConnect B-Series FCX Configuration Guide 603 53-1002266-01