Chapter 7: Quality of Service (QoS)
Configuring Scheduling
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Configuring Scheduling
This section includes:
•
•
•
•
Assigning a Priority Profile to an Interface
•
Assigning a WFQ Profile to an Interface
Scheduling Overview
Scheduling determines the priority among the queues. PTP 850 provides a unique hierarchical scheduling model
that includes four priorities, with Weighted Fair Queuing (WFQ) within each priority, and shaping per port and per
queue.
The scheduler scans the queues and determines which queue is ready to transmit. If more than one queue is ready
to 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, the
scheduler transmits frames from the queues based on a WFQ algorithm that determines the ratio of frames
per queue based on a predefined weight assigned to each queue.
Configuring Priority Profiles
Scheduling 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 eight
priority 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 Profile
Adding a Scheduler Priority Profile
To add a scheduler priority profile:
1.
Select
Ethernet > QoS > Scheduler > Priority Profiles
. The Scheduler Priority Profile page opens.
