HP Surestore Tape Library Model 10/180 HP Surestore Bridge FC 2/1 LV and FC 4/ - Page 230

SCC Addressing Option When a bridge is configured to use SCC addressing, the unit is capable of responding as a controller device to the FCP initiator or routing the FCP request to a specified bus:target:LUN. When a request using the peripheral device addressing method is received (an FCP command with the LUN field with bits 7 and 6 of byte 9 are set to 0), the unit routes the request to the internal processor, which acts on the command directly. When a request using the logical unit addressing method is received (bits 7 and 6 set to 10b), the request is routed to the bus:target:LUN as specified in the defined field. Host systems using SCC addressing will typically do initial device discovery using the peripheral device addressing method. On issuing an INQUIRY command to the bridge, the host will receive the bridge inquiry data, indicating the device type as a controller device (inquiry data indicated device type is 0xC). The host will then know that subsequent commands to the bridge attached devices will use the logical unit addressing method. The host can perform discovery by either walking through the bus:target:LUN values as would a standard SCSI driver, or by issuing a report LUNS command. This command is sent to the bridge (using the peripheral device addressing method), and the bridge returns a table indicating attached devices. The host can then perform actions on these bridge attached devices directly without having to perform discovery by issuing commands through all possible combinations. 232 SCC Addressing Option Appendix C