arbitrated loop physical address (AL_PA)

Arbitrated Loop Physical Address (AL_PA) is an 8-bit address used to identify a device with L_Port connected to the arbitrated loop of a Fibre Channel ( FC). The one byte from the AL_PA address is appended to the address identifier for the public L ports.

The AL_PA address space contains a total of 127 addresses, one of which is reserved for the fabric connection. The remaining 126 addresses are available for device connections within the arbitrated loop ( AL).