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4.7 Fibre Channel port configuration panel

This panel is used to modify the Fibre Channel parameters for the FibreBridge. Some parameters will

be “grayed out” if they do not apply to your model of the FibreBridge or if they have no effect based

upon the selected value of a related parameter.

ACK Mode (default = ACK1)
ACK 0 and ACK 1 are the two different methods for sending
the acknowledgment during Class 2 transfers. ACK 0 sends
an acknowledgement at the end of a sequence of data
packets. When ACK 1 is selected, an acknowledgement will
be sent after every data packet. The method of ACK must
match that of the initiator.
Addressing Mode (default = Soft)
Select either the Hard or Soft Fibre Channel Addressing
Mode. Hard Addressing enables the FibreBridge to always
use the AL-PA (Fibre Channel ID) value entered in the Hard
Address field. Soft Addressing will result in the FibreBri dge
taking a soft address in which the FibreBridge will be
assigned an AL-PA by the loop master during loop
initialization. This may cause the FibreBridge, and
connected SCSI devices, to be identified by a different AL-
PA each time the loop is rebooted.
Address Translation (default = Disabled)
Used to enable the Addressing Translation Mode within the
FibreBridge. Setting Address Translation to Disabled will
result in the FibreBridge using the default bit pattern of
LLLL TTTB to address your SCSI devices.
Setting the Address Translation to Enabled allows users to
configure the BTL pattern (FibreBridge Bus, Target ID,
LUN) for a configuration that matches the intended
installation.
A Fibre Channel host computer will address the
FibreBridge using a Fibre Channel ID and a Fibre Channel
LUN (ex. ID 4 LUN 7). The SCSI devices connected to the
FibreBridge will be addressed as Fibre Channel LUNs of
the FibreBridge ID (ex. ID 4 LUNs 0-6). The FibreBridge
has two independent busses that can each contain SCSI
targets 0 through 15 with multiple LUNs for each target.
The BTL translation method is used to combine each of
these unique SCSI device IDs into one Fibre Channel LUN,
while maintaining the requirement that each SCSI device
have an unique identifier.
Each SCSI device connected to the FibreBridge can be
identified by the FibreBridge Bus (B) it is connected to, the
SCSI Target ID (T) the device is set at and the SCSI LUN
(L). The selected bit pattern uses a binary translation to
combine the BTL information into one Fibre Channel LUN.
Leaving this field disabled is usually acceptable if you have
four or fewer SCSI target devices on FibreBri dge Bus 1 (se t
to SCSI IDS 0, 1, 2 and 3) and four or fewer on FibreBridge
Bus 2 (set to SCSI IDs 0, 1, 2 and 3). Configurations using
SCSI RAID controllers or those that require mo re than four
devices per bridge bus will require you to set this field to
enabled and to modify the Addressing Method field. Refer
to the Fibre Channel to SCSI Addressing chapter in the
FibreBridge manual or contact ATTO Technical Support if
you need further assistance.
Hard Address (default = 3)
Used to set the decimal value of the FC-AL hard address
after the Addressing Mode field is set to Hard. Allowable
values are between 0 and 126. Be sure to select an AL-PA
not in use by any other Fibre Channel device in the
arbitrated loop.
Arbitration Fairness (default = Enabled)
Used to enable or disable Arbitration Loop Fairness.
Fairness is an algorithm that assures all NL_Ports on an
arbitrated loop will have equal access to the loop. Each
NL_Port has an arbitration priority assigned to it based on
its AL_PA. When enabled, the fairness algorithm creates an
access window in which all NL_Ports are given an
opportunity to win access to the loop, regardless of assigned
priority. When disabled, a device with a high priority may
dominate the loop.
Some Fibre Channel devices are not compatible in the
execution of arbitration fairness algorithms. If you
experience intermittent behavior in terms of FibreBridge
performance or certain SCSI devices connected to the
FibreBridge are not detected by the host computer, try
disabling this setting.
Class 2 (default = Disabled)
Used to enable Class 2 Fibre Channel transfers. When
enabled, the target device (FibreBridge) will send an
acknowledge to the initiator indicating that data has been
received. The default mode of the FibreBridge uses Class 3
transfers in which the responsibility of verifying that data
has been properly transferred is left to the application
program. While Class 2 will result is fewer retries from the
application program, it requires more overhead to send the
actual acknowledge. Only set the bridge for Class 2
transfers if the initiating device also supports it.
FibreBridge Soft Fibre LUN (default = 7)
If Address Translation has been enabled, the value selected
will be the Fibre Channel LUN of the FibreBridge as
identified by all host computers. For example, if a value of
5 exists in this field and the FibreBridge hard address is set