Scc (Scsi Controller Command) Addressing Method - HP StorageWorks N1200 User Manual

Addressing Methods and Table Structures

SCC (SCSI Controller Command) Addressing Method

When a router is configured to use SCSI Controller Command addressing (SCC)
and a command is received, the router either will respond as a controller device to
the FCP Initiator or will route the FCP request to a specified BUS:TARGET:LUN.
If a request using the Peripheral Device Addressing method is received (an FCP
command with the LUN field bits 7 and 6 of byte 0 set to 0), the router routes the
request to the internal processor, which acts on the command directly. If a request
using the Logical Unit Addressing method is received (bits 7 and 6 set to 00x10),
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 router, the host will receive the router Inquiry data, indicating the device
type as a controller device (Inquiry data indicates device type is 0xC). The host
will then know that subsequent commands to router-attached devices will use the
Logical Unit Addressing method.
The host can perform discovery by either progressing 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 router (using the Peripheral
Device Addressing method). The router returns a table indicating the attached
devices. The host can then perform actions on these devices directly without
performing further discovery processing.
172 Network Storage Router N1200 User Guide