Reference Guide

Quality of service
Quality of service (QoS) manages the delay, jitter, bandwidth, and packet loss parameters on a network. OS10 devices examine each
received packet and place the packet into dierent classes of service (CoS) by assigning a trac class ID depending on the packet QoS
parameters.
QoS allows you to assign dierent behaviors to dierent trac classes. This QoS behavior tells the switch how to treat the trac as it
travels from the ingress interface, all the way until it is sent out the egress interface. You can assign dierent QoS behaviors to trac
classes including rate-limiting, rate-shaping, marking 802.1p or DSCP elds, queuing, and bandwidth management. QoS helps limit the rate
of control trac packets directed to the CPU.
Classify data trac
You can classify trac based on Layer 2 or Layer 3 header elds or on an incoming port. The packet header elds selected for matching are
called match criteria. Classication can be based on all or any of the match criteria. Dene class-maps for ingress classication of data
trac based on match criteria with a QoS type, and mark or tag classied trac with a trac class ID (qos-group). Use the queuing type
to dene class-maps for egress classication by matching the trac class ow IDs created during ingress classication (see Congure
class-map).
Classify control trac
Each set of pre-classied control trac towards the CPU is assigned a unique trac class ID. A control-plane type denes class-maps for
control-trac classication by matching the preassigned trac class ow IDs (qos-group).
Dene policy
Once the trac is classied into a class of service, dene policies to apply on selected trac classes. The policy represents the action (QoS
behavior) to be taken on the selected trac classes. Some actions are executed for ingress trac — called ingress policy actions. Allowed
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