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Software Configuration Guide—Release 12.2(25)SG
OL-7659-03
Chapter27 Configuring Quality of Service
Configuring QoS
CoS to DSCP map
(DSCP set from CoS values)
CoS 0 = DSCP 0
CoS 1 = DSCP 8
CoS 2 = DSCP 16
CoS 3 = DSCP 24
CoS 4 = DSCP 32
CoS 5 = DSCP 40
CoS 6 = DSCP 48
CoS 7 = DSCP 56
DSCP to CoS map
(CoS set from DSCP values)
DSCP 0–7 = CoS 0
DSCP 8–15 = CoS 1
DSCP 16–23 = CoS 2
DSCP 24–31 = CoS 3
DSCP 32–39 = CoS 4
DSCP 40–47 = CoS 5
DSCP 48–55 = CoS 6
DSCP 56–63 = CoS 7
Marked-down DSCP from DSCP map
(Policed-DSCP)
Marked-down DSCP value equals original DSCP value (no markdown)
Policers None
Policy maps None
Transmit queue sharing 1/4 of the link bandwidth
Transmit queue size 1/4 of the transmit queue entries for the port. The trans mit queue size of a
port depends on the type of port, ranging from 240 packets per transmit
queue to 1920 packets per transmit queue.
Transmit queue shaping None
DCSP-to-Transmit queue map DSCP 0–15 Queue 1
DSCP 16–31 Queue 2
DSCP 32–47 Queue 3
DSCP 48–63 Queue 4
High priority transmit queue Disabled
With QoS disabled
Interface trust state Trust DSCP
With QoS enabled With QoS enabled and all other QoS parameters at default values, QoS sets
IP DSCP to zero and Layer 2 CoS to zero in all traffic transmitted.
Interface trust state Untrusted
Table27-3 QoS Default Configuration (continued)
Feature Default Value