FibeAir IP-20C/S/E
User Guide
Ceragon Proprietary and Confidential
Page 493 of 597
18.6
Configuring Scheduling (CLI)
This section includes:
Overview of Egress Scheduling (CLI)
Configuring Queue Priority (CLI)
Configuring Interface Priority Profiles (CLI)
Attaching a Priority Profile to an Interface (CLI)
Configuring Weighted Fair Queuing (WFQ) (CLI)
18.6.1
Overview of Egress Scheduling (CLI)
Egress scheduling is responsible for transmission from the priority queues.
IP-20 uses a unique algorithm with a hierarchical scheduling model over the
three levels of the egress path that enables compliance with SLA
requirements.
The scheduler scans all the queues over all the service bundles, per interface,
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.
18.6.2
Configuring Queue Priority (CLI)
A priority profile defines the exact order for serving the eight priority queues
in a single service bundle. When you attach a priority profile to an interface, all
the service bundles under the interface inherit the profile.
The priority mechanism distinguishes between two states of the service
bundle:
Green State – Committed state
Yellow State – Best effort state
Green State refers to any time when the service bundle rate is below the user-
defined CIR. Yellow State refers to any time when the service bundle is above
the user-defined CIR but below the PIR.
You can define up to four Green priority profiles, from 4 (highest) to 1
(lowest). An additional four Yellow priority profiles are defined automatically
and cannot be changed or edited.
