Service Manual

Table Of Contents
Destination MAC address: 6 bytes
Source MAC address: 6 bytes
Ethernet Type/Length: 2 bytes
Payload: (variable)
Cyclic redundancy check (CRC): 4 bytes
Inter-frame gap (IFG): (variable)
You can optionally include overhead fields in rate metering calculations by enabling QoS rate adjustment.
QoS rate adjustment is disabled by default.
Specify the number of bytes of packet overhead to include in rate limiting, policing, and shaping
calculations.
CONFIGURATION mode
qos-rate-adjust overhead-bytes
For example, to include the Preamble and SFD, type qos-rate-adjust 8. For variable length
overhead fields, know the number of bytes you want to include.
The default is disabled.
The range is from 1 to 31.
Enabling Strict-Priority Queueing
In strict-priority queuing, the system de-queues all packets from the assigned queue before servicing any
other queues. You can assign strict-priority to one unicast queue, using the strict-priority command.
Policy-based per-queue rate shaping is not supported on the queue configured for strict-priority
queuing. To use queue-based rate-shaping as well as strict-priority queuing at the same time on a
queue, use the Scheduler Strict feature as described in Scheduler Strict .
The strict-priority supersedes bandwidth-percentage configuration.
A queue with strict priority can starve other queues in the same port-pipe.
Assign strict priority to one unicast queue.
CONFIGURATION mode
strict-priority
The range is from 1 to 3.
Weighted Random Early Detection
Weighted random early detection (WRED) is a congestion avoidance mechanism that drops packets to
prevent buffering resources from being consumed.
The WRED congestion avoidance mechanism drops packets to prevent buffering resources from being
consumed.
Traffic is a mixture of various kinds of packets. The rate at which some types of packets arrive might be
greater than others. In this case, the space on the buffer and traffic manager (BTM) (ingress or egress) can
be consumed by only one or a few types of traffic, leaving no space for other types. You can apply a
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Quality of Service (QoS)