HP StorageWorks Fabric OS 3.X Document Addendum (AA-RW24A-TE, January 2005)

Fabric OS reference guide
168 Fabric OS 3.x Document Addendum
The default virtual channel settings have already been optimized for switch performance.
Judiciously changing the default values might improve switch performance somewhat, but can
also severely degrade performance. You should not change these settings without fully
understanding the effects. See Table 14 for the virtual channel settings. Each field is described
after the table.
VC Link Control
Specifies the virtual channel used for N_Port-generated, Class 2 link control frames (ACKs,
P_BSYs, P_RJTs). Forces N_Port-generated link control frames to be sent, using a Class 2
data virtual channel when set to 0. When set to 1, the control frames are sent using a virtual
channel normally reserved for fabric-internal traffic.
This setting is configurable only when VC encoded address mode is set.
VC Class 2
Specifies the virtual channel used for Class 2 frame traffic. This setting is configurable only
when VC encoded address mode is set.
VC Class 3
Specifies the virtual channel used for Class 3 frame traffic. This setting is configurable only
when VC encoded address mode is set.
VC Multicast
Specifies the virtual channel used for multicast frame traffic. This setting is configurable only
when VC encoded address mode is set.
VC Priority
Specifies the class of frame traffic given priority for a virtual channel.
Zoning Operation Parameter
Table 15 specifies the zoning operation parameter. The field is described following the table.
Table 14: Virtual Channel Settings
Field Type Default Range
VC Link Control Number 0 0 to 1
VC Class 2 Number 2 2 to 5
VC Class 3 Number 3 2 to 5
VC Multicast Number 7 6 to 7
VC Priority 2Number2 2 to 3
VC Priority 3Number2 2 to 3
VC Priority 4Number2 2 to 3
VC Priority 5Number2 2 to 3
VC Priority 6Number3 2 to 3
VC Priority 7Number3 2 to 3