User's Manual

Technical Notes – QoS Features on BES50

• Strict Priority queuing operates in a pre-emptive fashion. Frames in the higher priority queues always

take precedence over frames in lower priority queues. A low priority queue will not be serviced as long

as there is a frame in one of the higher priority queues. When the highest priority queue is empty,

frames from the other queues are serviced based on their precedence (i.e. from the higher priority

queue to the lower priority queue). With strict priority queuing, it is possible that some queues may

never be serviced, causing frames dropped and starvation. Use of Strict Priority queuing must be used

with great care.

• With Weighted Round Robin queuing, each queue is assigned a weight which represents a relative

proportion of time during which the queue can send packets. This technique ensures each queue gets

appropriate share of bandwidth for transmitting its packets. With Weighted Round Robin, no priority is

assigned to the queues. Each queue sends frames in proportion to its configured weight.

BES50 uses WRR queuing by default. If the user decided to change the scheduling algorithm, navigate to the

Applications > Priority > Queue Mode panel

Figure 3: Scheduler Queuing Mode

When running in WRR, the weight assigned to each class are pre-defined and not user configurable. To view

the assigned weight for each class, navigate to the Applications > Priority > Queue Scheduling panel