Users Guide

Fabric OS Administrator’s Guide 417

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CS_CTL-based frame prioritization

Alternatively, the user can apply CS_CTL auto mode. The CS_CTL auto mode uses only three

CS_CTL values, as illustrated in Table 73.

NOTE

The values in the tables represent chassis-level configurations. For configuration details, refer to

“Using CS_CTL auto mode at the chassis level” on page 418, and “Considerations for using

CS_CTL-based frame prioritization” on page 418.

Supported configurations for CS_CTL-based frame prioritization

CS_CTL-based frame prioritization is supported on all 8-Gbps and 16-Gbps platforms.

All switches in the fabric should be running Fabric OS v6.0.0 or later.

NOTE

If a switch is running a firmware version earlier than Fabric OS v6.0.0, 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

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.

TABLE 72 Mapping of CS_CTL values to QoS priority for frame prioritization in CS_CTL default mode

CS_CTL value Priority

1–8 Low

9–16 Medium

17–24 High

TABLE 73 Mapping of CS_CTL values to QoS priority for frame prioritization in CS_CTL auto mode

CS_CTL value Priority

1Low

2Medium

3High