Chapter 32
Configuring QoS
Queueing and Scheduling on Ingress Queues
Figure 32-7
Figure 32-7
(DSCP or CoS value).
Determine ingress queue
number, buffer allocation,
and WTD thresholds.
Queue the packet. Service
the queue according to
SRR services the priority queue for its configured share before servicing the other queue.
Note
The switch supports two configurable ingress queues, which are serviced by SRR in shared mode only.
Table 32-1
Table 32-1
Ingress Queue Types
1
Queue Type
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.
1. The switch uses two nonconfigurable queues for traffic that is essential for proper network operation.
OL-13018-01
shows the queueing and scheduling flowchart for ingress ports.
Queueing and Scheduling Flowchart for Ingress Ports
Start
Read QoS label
Yes
Are thresholds
being exceeded?
No
the SRR weights.
Send packet to
the internal ring.
describes the queues.
Drop packet.
Cisco IE 3000 Switch Software Configuration Guide
Understanding QoS
32-13