SMC Networks 6152PL2 FICHE, Management Manual

Page: 743 / 818

Class of Service Commands
4-365
4
frame is an IEEE 802.1Q VLAN tagged frame, the IEEE 802.1p User Priority
bits will be used.
• This switch provides eight priority queues for each port. It is configured to use
Weighted Round Robin by default, which can be viewed with the show queue
bandwidth command. Inbound frames that do not have VLAN tags are
tagged with the input port’s default ingress user priority, and then placed in the
appropriate priority queue at the output port. The default priority for all ingress
ports is zero. Therefore, any inbound frames that do not have priority tags will
be placed in queue 0 of the output port. (Note that if the output port is an
untagged member of the associated VLAN, these frames are stripped of all
VLAN tags prior to transmission.)
Example
The following example shows how to set a default priority on port 3 to 5:
Related Commands
show interfaces switchport (4-232)
queue cos-map
This command assigns class of service (CoS) values to the priority queues (i.e.,
hardware output queues 0 - 3). Use the
no form set the CoS map to the default
values.
Syntax
queue cos-map queue_id [ cos1 ... cosn ]
no queue cos-map
• queue_id - The ID of the priority queue.
Ranges are 0 to 3, where 3 is the highest priority queue.
• cos1 .. cosn - The CoS values that are mapped to the queue ID. It is a
space-separated list of numbers. The CoS value is a number from 0 to 7,
where 7 is the highest priority.
Default Setting
This switch supports Class of Service by using four priority queues, with
Weighted Round Robin queuing for each port. Eight separate traffic classes
are defined in IEEE 802.1p. The default priority levels are assigned according
to recommendations in the IEEE 802.1p standard as shown below.
Console(config)#interface ethernet 1/3
Console(config-if)#switchport priority default 5
Table 4-89 Default CoS Values to Egress Queues
Queue
0 1 2 3
Priority
1,2 0,3 4,5 6,7