LevelOne GEL-1061, User Manual

Page: 195 / 500

Chapter 9
| Class of Service
Layer 2 Queue Settings
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the switch services each queue before moving on to the next queue. This
prevents the head-of-line blocking that can occur with strict priority queuing.
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If Strict and WRR mode is selected, a combination of strict service is used for the
high priority queues and weighted service for the remaining queues. The
queues assigned to use strict priority should be specified using the Strict Mode
field parameter.
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A weight can be assigned to each of the weighted queues (and thereby to the
corresponding traffic priorities). This weight sets the frequency at which each
queue is polled for service, and subsequently affects the response time for
software applications assigned a specific priority value.
Service time is shared at the egress ports by defining scheduling weights for
WRR, or one of the queuing modes that use a combination of strict and
weighted queuing.
◆
The specified queue mode applies to all interfaces.
Parameters
These parameters are displayed:
◆
Queue Mode
■
Strict – Services the egress queues in sequential order, transmitting all
traffic in the higher priority queues before servicing lower priority queues.
This ensures that the highest priority packets are always serviced first,
ahead of all other traffic.
■
WRR – Weighted Round-Robin shares bandwidth at the egress ports by
using scheduling weights, and servicing each queue in a round-robin
fashion. (This is the default setting.)
■
Strict and WRR – Uses strict priority on the high-priority queues and WRR
on the remaining queues.
◆
Queue ID – The ID of the priority queue. (Range: 0-7)
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Strict Mode – If “Strict and WRR” mode is selected, then a combination of strict
service is used for the high priority queues and weighted service for the
remaining queues. Use this parameter to specify the queues assigned to use
strict priority when using the strict-weighted queuing mode.
(Default: Disabled)
◆
Weight – Sets a weight for each queue which is used by the WRR scheduler.
(Range: 1-127; Default: Weights 1, 2, 4, 6, 8, 10, 12 and 14 are assigned to
queues 0 - 7 respectively)