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Cisco Catalyst Blade Switch 3020 for HP Software Configuration Guide
OL-8915-03
Chapter 32 Configuring QoS
Understanding QoS
Queueing and Scheduling on Ingress Queues
Figure 32-8
shows the queueing and scheduling flowchart for ingress ports.
Figure 32-8
Queueing and Scheduling Flowchart for Ingress Ports
Note
SRR services the priority queue for its configured share before servicing the other queue.
The switch supports two configurable ingress queues, which are serviced by SRR in shared mode only.
Table 32-1
describes the queues.
90564
Read QoS label
(DSCP or CoS value).
Determine ingress queue
number, buffer allocation,
and WTD thresholds.
Are thresholds
being exceeded?
Queue the packet. Service
the queue according to
the SRR weights.
Send packet to
the internal ring.
Drop packet.
Start
Yes
No
Table 32-1
Ingress Queue Types
Queue Type
1
1.
The switch uses two nonconfigurable queues for traffic that is essential for proper network operation.
Function
Normal
User traffic that is considered to be normal priority. You can configure three different
thresholds to differentiate among the flows. You can use the
mls qos srr-queue input
threshold
, the
mls qos srr-queue input dscp-map
, and the
mls qos srr-queue input
cos-map
global configuration commands.
Expedite
High-priority user traffic such as differentiated services (DF) expedited forwarding or
voice traffic. You can configure the bandwidth required for this traffic as a percentage
of the total traffic by using the
mls qos srr-queue input priority-queue
global
configuration command. The expedite queue has guaranteed bandwidth.
