Reference Guide

NOTE
If a switch is running a firmware version earlier than Fabric OS v6.3.0, the outgoing frames from that switch lose their priority.
High availability considerations for CS_CTL-based frame prioritization
If the standby CP is running a Fabric OS version earlier than 6.3.0 and is synchronized with the active CP, then you cannot enable
CS_CTL-based frame prioritization on the active CP. If the standby CP is not synchronized or if no standby CP exists, then enabling
CS_CTL-based frame prioritization succeeds.
Enabling CS_CTL-based frame prioritization on ports
Make sure that the CS_CTL mode-enabled source and destination are zoned together.
When you enable CS_CTL-based frame prioritization, you must enable it on both the source port and the destination port, so that the
frames returned from the destination port for a given exchange always have the same CS_CTL prioritization as the frames originating
from the source port.
1. Connect to the switch and log in to an account that has admin permissions.
2. Enable CS_CTL mode:
portcfgqos --enable [slot/]port csctl_mode
3. Enter y at the prompt to override QoS zone-based traffic prioritization.
Disabling CS_CTL-based frame prioritization on ports
When you disable CS_CTL-based frame prioritization, QoS zone-based traffic prioritization is restored if it had been previously enabled.
1. Connect to the switch and log in to an account that has admin permissions.
2. Disable CS_CTL mode using the portCfgQos command with the --disable option:
portcfgqos --disable [slot/]port csctl_mode
Alternatively, you can use the --default option to disable CS_CTL mode and set QoS to auto-enable (AE):
portcfgqos --default [slot/]port
Using CS_CTL auto mode at the chassis level
You can use the CS_CTL QoS mode options for the configureChassis command to change the chassis-wide default mode, as in the
following example.
switch:admin> configurechassis
Configure...
cfgload attributes (yes, y, no, n): [no]
Custom attributes (yes, y, no, n): [no]
system attributes (yes, y, no, n): [no]
fos attributes (yes, y, no, n): [no] y
CSCTL QoS Mode (0 = default; 1 = auto mode): (0..1) [0] 1
Set CSCTL QoS Mode to 1 to enable auto mode, establishing the settings shown in Table 77 on page 398. Set CSCTL QoS Mode to 0
to disable auto mode and revert to default settings, shown in Table 76 on page 398.
This is a chassis-level configuration. It does not provide options to enable CS_CTL QoS on the ports.
Optimizing Fabric Behavior
Brocade Fabric OS Administration Guide, 8.0.1
53-1004111-02 399