Brocade TurboIron 24X Series Configuration Guide - Manual (Page 1077)

Brocade TurboIron 24X Series Configuration Guide 1043
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Configuring the QoS mappings
Notice that DSCP values range from 0 – 63, whereas the internal forwarding priority values range
from 0 – 7. Any DSCP value within a given range is mapped to the same internal forwarding priority
value. For example, any DSCP value from 8 – 15 maps to priority 1.
After performing this mapping, the device maps the internal forwarding priority value to one of the
hardware forwarding queues.
Table 172 list the default mappings of internal forwarding priority values to the hardware
forwarding queues.
Devices supports seven priorities instead of eight when sFlow is enabled. QoS queue 1 is reserved
for sFlow and not used by other packets. Any non-sFlow packets assigned to QoS queue 1 will be
directed to QoS queue 0.
You can change the DSCP -> internal forwarding mappings. You also can change the internal
forwarding priority -> hardware forwarding queue mappings.
Changing the DSCP –> internal forwarding priority mappings
To change the DSCP –> internal forwarding priority mappings for all the DSCP ranges, enter
commands such as the following at the global CONFIG level of the CLI.
TurboIron(config)#qos-tos map dscp-priority 0 2 3 4 to 1
TurboIron(config)#qos-tos map dscp-priority 8 to 5
TurboIron(config)#qos-tos map dscp-priority 16 to 4
TurboIron(config)#qos-tos map dscp-priority 24 to 2
TurboIron(config)#qos-tos map dscp-priority 32 to 0
TurboIron(config)#qos-tos map dscp-priority 40 to 7
TurboIron(config)#qos-tos map dscp-priority 48 to 3
TurboIron(config)#qos-tos map dscp-priority 56 to 6
TurboIron(config)#
The first command in the above example maps priority 1 to DSCP values 0, 2, 3, and 4.
6 48 – 55
7 (highest priority queue) 56 – 63
TABLE 172 Default mappings of internal forwarding priority values
Internal forwarding priority Forwarding queues
0 (lowest priority queue) qosp0
1 qosp1
2 qosp2
3 qosp3
4 qosp4
5 qosp5
6 qosp6
7 (highest priority queue) qosp7
TABLE 171 Default DSCP to internal forwarding priority mappings (Continued)
Internal forwarding priority DSCP value