Cisco Catalyst 3750 - Queueing and Scheduling of Egress Queue-Sets

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Catalyst 3750 Metro Switch Software Configuration Guide
78-15870-01
Chapter 26 Configuring QoS
Understanding QoS
Queueing and Scheduling of Egress Queue-Sets
Figure 26-8 shows the egress queue-set queueing and scheduling flowchart.
Figure 26-8 Egress Queue-Set Queueing and Scheduling Flowchart
98884
Receive packet from
the internal ring.
Read QoS label
(DSCP or CoS value).
Determine egress queue
number and threshold
based on the label.
Are thresholds
being exceeded?
Send the packet out the
standard port, to the
input of the hierarchical
egress queueing and
scheduling, or both.
Queue the packet. Service
the queue according to
the SRR weights.
Drop packet.
Start
Done
Ye s
No
Rewrite DSCP,
CoS, or both values,
as appropriate.