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2-62Mapping DSCP Priority
The DSCP is six bits wide, allowing coding for up to 64 different
forwarding behaviors. The DSCP replaces the ToS bits, and it retains
backward compatibility with the three precedence bits so that non-DSCP
compliant, ToS-enabled devices, will not conflict with the DSCP mapping.
Based on network policies, different kinds of traffic can be marked for
different kinds of forwarding. The DSCP default values are defined in the
following table. Note that all the DSCP values that are not specified are
mapped to CoS value 0.
Command Attributes
DSCP Priority Table – Shows the DSCP Priority to CoS map.
Class of Service Value – Maps a CoS value to the selected DSCP
Priority value. Note that “0” represents low priority and “7” represent
high priority.
Web – Click Priority/IP DSCP Priority. Select a port or trunk from the
Interface field (note that settings apply to all interfaces). Selec t a DSCP
priority value from the DSCP Priority Table by clicking on it with your
cursor, enter a value in the Class of Ser vice Value field, and then click
“Apply.” Be sure to also select “IP DSCP” from the IP Precedence/DSCP
Priority Status menu.
IP DSCP Value CoS Value
00
81
10, 12, 14, 16 2
18, 20, 22, 24 3
26, 28, 30, 32, 34, 36 4
38, 40, 42 5
48 6
46, 56 7