20-19
Catalyst 3550 Multilayer Switch Software Configuration Guide
78-11194-03
Chapter 20 Configuring QoS
Configuring QoS
The default port CoS value is 0.
The default port trust state on all ports is untrusted.
No policy maps are configured.
No policers are configured.
The default CoS-to-DSCP map is shown in
Table 20-3 on page 20-39
.
The default IP-precedence-to-DSCP map is shown in
Table 20-4 on page 20-40
.
The default DSCP-to-CoS map is shown in
Table 20-5 on page 20-42
.
The default DSCP-to-DSCP-mutation map is a null map, which maps an incoming DSCP value to the
same DSCP value.
The default policed-DSCP map is a null map, which maps an incoming DSCP value to the same DSCP
value (no markdown).
The default DSCP-to-switch-priority map maps DSCPs 0 to 15 to priority 0, DSCPs 16 to 31 to
priority 1, DSCPs 32 to 47 to priority 2, and DSCPs 48 to 63 to priority 3.
Table 20-2 Default QoS Parameters when QoS is Enabled
Port
Type
QoS
State
Egress traffic
(DSCP and CoS
Value)
Queue
Queue
Weights
Tail-drop
Thresholds
CoS Mapping
to Queue
Gigabit-capable
Ethernet ports
Enabled
(no
policing)
DSCP=0
CoS=0
(0 means
best-effort
delivery.)
Four queues are
available (no
expedite queue).
Each queue has
the same weight.
100%, 100%
WRED is
disabled.
0, 1: queue 1
2, 3: queue 2
4, 5: queue 3
6, 7: queue 4
10/100 Ethernet
ports
Enabled
(no
policing)
DSCP=0
CoS=0
(0 means
best-effort
delivery.)
Each of the eight
minimum-reserve
levels have a buffer
size of 100 packets.
The queue selects
the level.
Each queue has
the same weight.
–
0, 1: queue 1
2, 3: queue 2
4, 5: queue 3
6, 7: queue 4
