HP StorageWorks MSA 2/8 HP StorageWorks Fabric OS V3.1.x/4.1.x Reference Guide - Page 154

Fabric OS Commands Core Switch PID Format (V3.1.x only) Per-frame Route Priority Long Distance Fabric This is used to set the 256 port PID format that is used for core switches. This option enables single Domain port density higher than 16. VC Encoded Address Mode and Core Switch PID Format are mutually exclusive. They cannot both be enabled at the same time. All switches in the fabric must have this parameter set the same. In addition to the eight virtual channels used in frame routing priority, support is also available for per-frame based prioritization when this value is set. When Per-frame Route Priority is set to 1, the virtual channel ID is used in conjunction with a frame header to form the final virtual channel ID. When this mode is set to 1, ISLs in a fabric can be up to 100Km long. The exact distance level is determined by the per-port configuration on the E_Ports of each ISL. Both E_Ports in an ISL must be configured to run the same long distance level, otherwise, the fabric will be segmented. The Extended Fabric License is required to set this mode. Virtual Channel Settings The switch enables fine tuning for a specific application, by configuring the parameters for eight virtual channels. The first two virtual channels are reserved for switch internal functions and are not available for modification. The default virtual channel settings have already been optimized for switch performance. Changing the default values can improve switch performance, but can also degrade performance. Do not change these settings without fully understanding the effects of the changes. The Virtual Channel Setting fields are as follows: Table 3: Configure Command Virtual Channel Settings Field VC Priority 2 VC Priority 3 VC Priority 4 VC Priority 5 VC Priority 6 VC Priority 7 Default 2 2 2 2 3 3 Range 2 to 3 2 to 3 2 to 3 2 to 3 2 to 3 2 to 3 :A description of the Virtual Channel Setting field follows: 154 Fabric OS Version 3.1.x/4.1.x Reference Guide