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QoS mapping configuration
You can optionally change the following QoS mappings:
•
DSCP to internal forwarding priority
•
VLAN priority (802.1p) to hardware forwarding queue, as described in
Changing the VLAN priority 802.1p to hardware forwarding
queue mappings
on page 35
The mappings are globally configurable and apply to all interfaces.
Default DSCP to internal forwarding priority mappings
The DSCP values are described in RFCs 2474 and 2475. The following table lists the default mappings of DSCP values to internal
forwarding priority values.
TABLE 11 Default DSCP to internal forwarding priority mappings
Internal forwarding priority
DSCP value
0 (lowest priority queue)
0–7
1
8–15
2
16–23
3
24–31
4
32–39
5
40–47
6
48–55
7 (highest priority queue)
56–63
Notice that DSCP values range from 0 through 63, whereas the internal forwarding priority values range from 0 through 7. Any DSCP value
within a given range is mapped to the same internal forwarding priority value. For example, any DSCP value from 8 through 15 maps to
priority 1.
After performing this mapping, the device maps the internal forwarding priority value to one of the hardware forwarding queues.
On ICX devices, you can use QoS queue 1 for priority traffic, even when sFlow is enabled on the port.
You can change the DSCP to internal forwarding mappings. You also can change the internal forwarding priority to hardware forwarding
queue mappings.
QoS scheduling and queuing methods
Scheduling
is the process of mapping a packet to an internal forwarding queue based on its QoS information and servicing the queues
according to a queuing method.
The following QoS queuing methods are supported for the FastIron devices:
•
Weighted Round Robin (WRR)—This method ensures that all queues are serviced during each cycle. A WRR algorithm is used to
rotate service among the eight queues on the FastIron devices. The rotation is based on the weights you assign to each queue.
This method rotates service among the queues, forwarding a specific number of packets in one queue before moving on to the
next one.
Quality of Service
QoS scheduling and queuing methods
Ruckus FastIron QoS and Traffic Management Configuration Guide, 08.0.70
Part Number: 53-1005294-01
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