Fabric OS Administrator's Guide v7.0.0 (53-1002148-02, June 2011)

414 Fabric OS Administrator’s Guide
53-1002148-02
CS_CTL-based frame prioritization
20
License requirements for SID/DID prioritization
Both CS_CTL-based frame prioritization and QoS zone-based traffic prioritization require the
Adaptive Networking license.
An Adaptive Networking license must be installed on every switch that is in the path between a
configured device pair.
When you install the Adaptive Networking license, QoS zone-based traffic prioritization is
automatically enabled on the E_Ports, except for long-distance E_Ports. For long-distance E_Ports,
you must manually enable QoS zone-based traffic prioritization after you install the license.
ATTENTION
To preserve existing trunk groups, before you install the Adaptive Networking license, manually
disable QoS on the 8 Gbps ports. See “Trunking considerations before you install the Adaptive
Networking license” on page 416 for more information.
CS_CTL-based frame prioritization
CS_CTL-based frame prioritization allows you to prioritize the frames between a host and target as
having high, medium, or low priority, depending on the value of the CS_CTL field in the FC frame
header.
High, medium, and low priority frames are allocated to different virtual channels (VCs). High priority
frames receive more VCs than medium priority frames, which receive more VCs than low priority
frames. The virtual channels are allocated according to the CS_CTL value, as shown in Table 73.
TABLE 72 Comparison between CS_CTL-based and QoS zone-based prioritization
CS_CTL-based frame prioritization QoS zone-based traffic prioritization
Requires Adaptive Networking license. Requires Adaptive Networking license.
Must be manually enabled after you install the license. Automatically enabled when you install the license.
No zones are required. Requires you to create QoS zones.
Enabled on F/FL_Ports. Enabled on E_Ports.
Takes precedence over QoS zone-based prioritization. Is overridden by CS_CTL-based prioritization.
Priority is defined by CS-CTL field in frame header. Priority is defined by name of QoS zone.
Prioritization is on a frame-basis. Prioritization is on a flow-basis.
Setup steps:
• Enable QoS on F/FL_Ports.
Setup steps:
• Create QoS zones with host/target members.
• Add the QoS zones to the zone configuration.
• Save and then and enable the zone configuration.
• Enable QoS on E_Ports.
TABLE 73 Virtual channels assigned to QoS priority
CS_CTL value Priority Number of VCs VCs assigned
1 – 8 High priority 4 10, 11, 12, 13
9 – 16 Medium priority 4 2, 3, 4, 5
17 – 24 Low priority 2 8, 9