Dell PowerConnect 5212, System User'S Manual

Page: 59 / 110

Console(config)#bridge-ext gvrp
Console(config)#
Class of Service
Class of Service (CoS) allows you to assign priority to data packets when traffic in the switch is buffered due to congestion. This switch supports CoS by using
four priority queues for each port. Data packets in a port's high-priority queue will be transmitted before packets in the lower-priority queues.
The Class of Service page allows you to set the default priority for each port or trunk, and to configure the mapping of frame priority tags to the switch's four
priority queues. The page includes links to the following options:
l
Port Settings — Sets the default priority for each port
l
Trunk Settings — Sets the default priority for each trunk
l
Traffic Classes — Configures the mapping of IEEE 802.1p priority tags to the switch's four traffic class queues
l
Queue Scheduling — Configures Weighted Round Robin (WRR) queueing for the switch ports
l
Layer 3/4 Priority — Configures the mapping of IP Precedence/DSCP values or IP TCP/UDP port numbers to the switch's four priority queues
Port Settings
In the Port Settings page, you can specify the default port priority for each port on the switch. All packets entering the switch that are untagged (do not
already have a priority value) are tagged with the specified default port priority and then sorted into the appropriate priority queue at the output port.
For each port listed in the Port column, you can assign the default port priority (from 0 to 7) to untagged frames received on the port. The default setting for
ports is 0.
NOTICE: The IEEE 802.1p tags specify eight levels of priority, from the lowest (0) to the highest (7). IP Precedence or IP DSCP values are mapped to
these priority tag levels, and the priority levels are mapped directly to the switch's four traffic class queues.
CLI Commands
The following table summarizes the equivalent CLI command for items in the Class of Service/Port Settings page.
Example
Command Usage
switchport priority default default-
priority-id
Sets a priority for the incoming untagged frames or the priority of frames received by the device connected to the
specified interface