Configuration manual

You can apply the same policy map to multiple interfaces, and you can modify a policy map after you
apply it.
Enabling QoS Rate Adjustment
By default, while rate limiting, policing, and shaping, the Dell Networking OS does not include the
Preamble, SFD, or the IFG fields. These fields are overhead; only the fields from MAC destination address
to the CRC are used for forwarding and are included in these rate metering calculations.
The Ethernet packet format consists of:
• Preamble: 7 bytes Preamble
• Start frame delimiter (SFD): 1 byte
• 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, and no qos-rate-adjust is listed in the running-
configuration
• Include a specified 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, enter 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
Strict-priority means that the Dell Networking OS de-queues all packets from the assigned queue before
servicing any other queues.
• The strict-priority supersedes bandwidth-percentage and bandwidth-weight
percentage configurations.
• A queue with strict priority can starve other queues in the same port-pipe.
• If more than two strict priority queues are configured, the strict priority queue with a higher queue
number is scheduled first.
• Assign strict priority to one unicast queue.
CONFIGURATION mode
strict-priority
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Quality of Service (QoS)