Chapter 7: Quality of Service (QoS) Configuring Schedulingphn-3963_008v000Page 7-34Configuring SchedulingThis section includes:• Scheduling Overview• Configuring Priority Profiles• Configuring WFQ Profiles• Assigning a Priority Profile to an Interface• Assigning a WFQ Profile to an InterfaceScheduling OverviewScheduling determines the priority among the queues. PTP 850 provides a unique hierarchical scheduling modelthat includes four priorities, with Weighted Fair Queuing (WFQ) within each priority, and shaping per port and perqueue.The scheduler scans the queues and determines which queue is ready to transmit. If more than one queue is readyto transmit, the scheduler determines which queue transmits first based on:• Queue Priority – A queue with higher priority is served before lower-priority queues.• Weighted Fair Queuing (WFQ) – If two or more queues have the same priority and are ready to transmit, thescheduler transmits frames from the queues based on a WFQ algorithm that determines the ratio of framesper queue based on a predefined weight assigned to each queue.Configuring Priority ProfilesScheduling priority profiles determine the queue priority. Each profile contains eight CoS-based priorities,corresponding to eight queues in an interface to which the profile is assigned. You can configure up to eightpriority profiles. A ninth profile, Profile ID 9, is pre-configured. You can configure Green priorities from 4 (highest)to 1 (lowest). An additional four Yellow priority profiles are defined automatically.This section includes:• Adding a Scheduler Priority Profile• Editing a Service Scheduler Priority Profile• Deleting a Scheduler Priority ProfileAdding a Scheduler Priority ProfileTo add a scheduler priority profile:1. Select Ethernet > QoS > Scheduler > Priority Profiles. The Scheduler Priority Profile page opens.
