Type of QoS Scheduling
Switch1 (enable) show port capabilities 10/3
Model WS-X6248-RJ-45
Port 3/1
Type 10/100BaseTX
Speed auto,10,100
Duplex half,full
Trunk encap type 802.1Q,ISL
Trunk mode on,off,desirable,auto,nonegotiate
Channel yes
Broadcast suppression percentage(0-100)
Flow control receive-(off,on),send-(off)
Security yes
Dot1x yes
Membership static,dynamic
Fast start yes
QOS scheduling rx-(1q4t),tx-(2q2t)
CoS rewrite yes
ToS rewrite DSCP
UDLD yes
Inline power no
AuxiliaryVlan 1..1000,1025..4094,untagged,dot1p,none
SPAN source,destination
COPS port group 3/1-48
Link debounce timer yes
Dot1q-all-tagged yes
Since 1q4t has only 1 queue, all incoming frames will be placed
in this single queue. However, if the queue starts to become congested, frames
will be dropped based on their CoS values. The following lists the defaults for
each CoS value:
-
CoS 0 and 1 are mapped to threshold 1 (set at 50 percent)
-
CoS 2 and 3 are mapped to threshold 2 (set at 60 percent)
-
CoS 4 and 5 are mapped to threshold 3 (set at 80 percent)
-
CoS 6 and 7 are mapped to threshold 4 (set at 100
percent)
Any incoming packet with CoS setting of 0 or 1 that is mapped
to threshold 1 will be dropped if the port buffer is at 50 percent or higher.
The show qos info command in Example 8-5 shows the default mapping for CoS and its
associated drop threshold level on a Catalyst switch.