ATTO Technology ATTO FibreBridge 2350C, Installation And Operation Manual

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ATTO Technology Inc. FibreBridge Installation and Operation Manual
3.1.1 Route addressing
The ATTO FibreBridge allows parallel SCSI devices to participate in a Fibre Channel arbitrated loop
or on a fabric. Fibre Channel and parallel SCSI use different models to address devices. The
FibreBridge translates between these addressing models.
The chart below is a simplified overview of data
and control flow between the application and the
SCSI device through a number of stages.
Fibre Channel World Wide Name (WWN)
The Institute of Electrical and Electronics
Engineers (IEEE) assigns each manufacturer a
unique Company ID. The Device ID field
contains a unique value assigned by ATTO
Technology to every Fibre Channel product
produced by ATTO Technology.
Each Fibre Channel device is assigned a unique
World Wide Name (WWN). The WWN identifies
all Fibre Channel devices. The 64-bit WWN has
the following format:
Arbitrated Loop Port Address (AL_PA)
On a Fibre Channel Arbitrated Loop, the
FibreBridge appears at a single Arbitrated Loop
Port Address (AL_PA). Each device on an
arbitrated loop is assigned a unique AL_PA
during loop initialization. The FibreBridge
supports both modes of AL_PA assignment,
commonly referred to as hard and soft addressing.
Soft addressing
allows the loop initialization
master to assign the FibreBridge a unique AL_PA
during the loop initialization process. The AL_PA
assigned cannot be determined before loop
initialization. For example, adding new devices to
an arbitrated loop may change the AL_PA
assigned to the FibreBridge.
Hard addressing
allows a predetermined AL_PA
to be assigned to the FibreBridge. The
FibreBridge will try to acquire the desired hard
AL_PA. If another device has already been
assigned the specified AL_PA, the FibreBridge
will acquire a currently unassigned AL_PA.
The default mode is soft addressing.
Addressing devices
SCSI devices connected to the FibreBridge also
show up as Fibre Channel LUNs to the host
computer. SCSI devices must be on the same
addressing level as the SCSI portion of the
FibreBridge. The FibreBridge SCSI ID must be
set to a different SCSI ID from the other devices
on the same bus.
Application
Read & write data
Operation
System
SCSI LUN addressing in OS
native form
Host Bus
Adapter
Maps OS native LUNs
FCP
(SCSI)
FCP_CMD: LUN plus CDB
plus data
FibreBridge
Parse Fibre port and Fibre
LUN into SCSI
BUS:Target:LUN
SCSI bus
Transport SCSI address, CDB
and data to/from SCSI device
SCSI
device
SCSI device operation
Field
Name
WWN
Format
Company ID Device ID
Byte 0 1 2 3 4 5 6 7
Value 20 00 00 10 86 xx xx xx