StorageTek StorageNet SCSI-3 - Manual (Page 22)

FCP Constructs
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FCP Constructs
Before initiating any FCP request, the Nx_Port associated with the SES Application Client
(FCP Initiator) must complete an N_Port Login (
PLOGI ) with the Management Server in Class
2 or 3.
Note: The destination address in the PLOGI request must be set to FFFFFAh . The FCP
Process Login (PRLI) is not required by the SESD.
The format of an FCP Command ( FCP_CMND ), FCP Transfer Ready ( FCP_XFER_RDY ), FCP
Data ( FCP_DATA ) and FCP Response ( FCP_RSP ) conforms to those defined in the SCSI-3
Fibre Channel Protocol (FCP), Revision 12, X3T10/269, working draft.
Table 3-2 gives a brief description of the FCP Information Unit.
FCP Command Information Unit
Table 3-3 shows the FCP_CMND Information Unit (IU) that carries either a SCSI command to
be executed or a task management request to be performed. It contains the values and control
fields defined in its payload.
Report LUNs Contains information returned from SESD containing the LUNs
attached to the SESD.
Request Sense Used to sense information from the SESD.
Send Diagnostic Used to configure/diagnose a logical unit.
Test Unit Ready Used to test an LUNs operation state.
Reject Contains information and status about a unit’s failure.
Table 3-2 FCP Information Unit Descriptions
FCP Information Unit Description
FCP_CMND The Information Unit contains a SCSI Command to be executed or a task
management request on a target.
FCP_XFER_RDY The Information Unit indicates that the target is ready to perform the data
transfer associated with a FCP_CMD.
FCP_DATA The data associated with an I/O operation.
FCP_RSP The Information Unit contains status and sense information
Table 3-1 Constructs, Commands and Diagnostic Pages (Continued)
Command Description