Brocade FastIron Ethernet Switch Traffic Management Guide - Manual (Page 35)

Each port on the supported modules corresponds to a front-end panel port. By default, trust VLAN
priority is enabled.
NOTE
For all ports in the other FastIron SX modules, ACL should be used to implement the trust DSCP mode.
For example, to enable trust DSCP on interface ethernet 1/48 on the SX-FI48GPP module, enter the
following command.
Syntax: [no] trust dscp
To disable the configuration, use the no form of the command.
Configuring QoS mapping configuration
You can optionally change the following QoS mappings:
• DSCP to internal forwarding priority
• VLAN priority (802.1p) to hardware forwarding queue
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.
Default DSCP to internal forwarding priority mappings TABLE 19
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.
Configuring QoS mapping configuration
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