Seagate Fibre Channel Interface - Manual (Page 53)

Fibre Channel Interface Manual, Rev. D 39
Loop Initialization Previously Assigned (LIPA)
20-byte payload
The loop master transmits the bit map resulting from the LIFA.
The L_Port checks to see if the bit that corresponds to its previously acquired AL_PA is set. If not, the L_Port
sets it to ‘1’. If the L_Port’s bit has already been set by another port, it will attempt to assume a soft-assigned
AL_PA (LISA).
The L_Port then retransmits the LIPA frame.
Loop Initialization Hard Assigned (LIHA)
20-byte payload
The loop master transmits the bit map resulting from the LIPA.
The L_Port checks to see if the bit that corresponds to its hard address is set (usually using switches or jump-
ers). If not, the L_Port sets it to ‘1’. If the L_Port’s bit has already been set by another port, it will attempt to
assume a soft-assigned AL_PA (LISA).
The L_Port then retransmits the LIHA frame.
11030000 16-byte bit map of AL_PAs
Bit position
0 1 2 3 4 5 6 7 8 ... 128
AL_PA positions -- 00 01 02 04 08 0F 10 17 ... EF
Switch address -- 7E 7D 7C 7B 7A 79 78 77 ... 00
Bit map content
L 0 0 0 1 0 0 0 0 ... 0
Example The L_Port had a previously assigned AL_PA of 4 which was
not already set by another port, so it set the bit at position 4 to
‘1’.
The L_Port at AL_PA 4 claims its’
previously assigned address.
11040000 16-byte bit map of AL_PAs
Bit position
0 1 2 3 4 5 6 7 8 ... 128
AL_PA positions -- 00 01 02 04 08 0F 10 17 ... EF
Switch address -- 7E 7D 7C 7B 7A 79 78 77 ... 00
Bit map content
L 0 0 0 1 0 0 0 1 ... 0
Example The L_Port had a hard address set by switch or jumper at
AL_PA 8 which was not already set by another port, so it set the
bit at position 8 to ‘1’.
The L_Port at AL_PA 8 claims its’
preferred (hard-assigned) address.