Brocade Web Tools Administrator's Guide - Supporting Fabric OS v7.0.0 (53-1002152-01, March 2012)

230 Web Tools Adminstrator’s Guide
53-1002152-01
Quality of Service configuration
18
• Link Aggregation Group (LAG) configuration (mandatory)—Ports must be configured before they
can be placed into a LAG. The parameters applied to the LAG reflects on each port that is
member of the LAG.
• VLAN configuration (optional)—Port and LAG names are referenced in VLAN configuration, and
must be defined before you can successfully complete a VLAN configuration.
• Login group configuration (optional)—Login group configuration is not dependent on any of the
above configurations. It can be done as a separate task.
Quality of Service configuration
As a general concept, Quality of Service (QoS) is a mechanism for classifying and scheduling data
traffic based on priority settings. QoS can be used to control traffic congestion, allocate bandwidth,
and carry data traffic with different characteristics over a common interface.
The following two configuration options are available:
• You can edit the DCB map. The DCB map defines priority and priority group tables that support
Enhanced Transmission Selection (ETS). ETS allows allocation of bandwidth to different traffic
classes. DCB maps also allow you to enable Priority Flow Control (PFC).
• You can create a traffic class map. A traffic class map can be used to map a specific class of
traffic to a specific Class of Service (CoS).
Editing the DCB map
The DCB map defines priority and priority group tables that support Enhanced Transmission
Selection (ETS). ETS allows bandwidth to be allocated based on priority settings through an
exchange of priority group tables.
To edit the DCB map, perform the following steps.
1. Select the DCB tab on the Switch Administration panel.
2. Select the QoS tab.
3. Select the DCB Map tab.
4. Select the default DCB map, and click Edit.
The DCB Map Configuration dialog box displays.
5. Enter a precedence value in the Precedence field.
The value is specified as a number. The allowable range is 1 to 100. The default is 1.
The precedence value controls QoS scheduling policies. The scheduler gives precedence to the
highest precedence value.
When the DCB Map Configuration dialog box displays, the default values shown in the Priority
Group Map match the IEEE 802.1Q recommendation for systems supporting eight traffic
classes. The Priority Group Map displays the Layer 2 Cos values mapped to Priority Group ID
(PGID). PGID values are in the form
<policy>.<priority>. A policy value of 15 indicates
Priority values run from 0 (highest priority) to 7 (lowest priority). Note that this is contrary to the
CoS values, which run from 7 (highest priority) to 0 (lowest priority).
6. Create a new priority group by clicking Add next to the Priority Group table.