FC-AL Features
96122 • Revision: F Chapter 5 Fibre Channel Operations 49
Selective Reset
Selective resets perform a reset on the receiving port. These resets are helpful for
error recovery or reconfiguration of the loop. Any NL_Port that uses a selective
reset transmits a LIP(AL_PD,AL_PS). Refer to TABLE 5-28 for clearing effects.
■ AL_PD field contains the address of the port being reset
■ AL_PS contains the address of the port issuing the reset
Loop Failures
A loop failure is any of the following:
■ A loss of signal
■ A loss of synchronization for longer than R_T_TOV (For more information on
R_T_TOV, see “Timers” on page 65.)
If a Loop Failure occurs, the L_Port that detects the failure issues a LIP(F8,AL_PS)
if it has a valid AL_PA, or LIP(F8,F7) if it doesn’t.
Loop Initialization Loop Position
StorageTek libraries support the process of Loop Initialization Loop Position (LILP)
by retransmitting this sequence when required.
Completion Processes
The following processes occur after loop initialization.
Private Loop Initialization Completion
At this point in loop initialization, a private loop library has completed
initialization. It has acquired a private loop address of 00 00 xx. The xx is its
assigned AL_PA.
The library now waits for initiators, on this loop only, to complete a Port Login
(PLOGI), to complete a Process Login (PRLI), and then to start executing
commands.
Public Loop Initialization Completion
The public loop library has at this point acquired a loop address of 00 00 xx at this
point in initialization, where xx is its assigned AL_PA.
Next, the library will attempt a Fabric Login (FLOGI) with the loop FL_Port. If the
login is not successful, the library will revert back to private loop operation (see
“Private Loop Initialization Completion” on page 49).
With the successful completion of the FLOGI, the library has now acquired its
public loop address: DD AA xx. DD is the fabric domain; AA is the fabric area; and
xx is the AL_PA.
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