I have a Fiber Channel HBA (Emulex LPe12000) with two ports for transceivers. I also have two LTO-4 tape drives with two ports each. I don't have an FC switch or other FC hardware, but I have identical 8 GBit / s transceivers.
To my mind, this is an arbitrated loop, or FC-AL. I thought it should be "Dual Point-to-Point", but Linux claims it is a loop (see dmesg below).
At this time, I have connected each unit to an HBA port (blue cables below), but I wonder if there is any reason / advantage to also connect each tape drive to each other, to "close" the loop.
( 6.258389) scsi host12: Emulex LPe12000 PCIe Fibre Channel Adapter on PCI bus 01 device 01 irq 60 ( 7.016430) lpfc 0000:01:00.0: 0:1303 Link Up Event x1 received Data: x1 x1 x10 x2 x0 x0 0 ( 7.017855) lpfc 0000:01:00.0: 0:1309 Link Up Event npiv not supported in loop topology