The figure shows the flow between 6 types of objects: ASM Disk, Quorum Disk Device, Multipath Device, iSCSI Device, iSCSI Target, and Logical Volume. These objects appear in the illustration in the listed order, from top to bottom.
The top object is the ASM disk, and it communicates with the Quorum disk device.
The Quorum Disk Device communicates with the ASM disk and the Multipath Device.
The Multipath device communicates with the two iSCSI devices using ib0 and ib1, and also with the Quorum disk device.
Each iSCSI device communicates with the iSCSI target and the Multipath device.
The iSCSI target communicates with the Logical Volume.
The bottom object is Logical Volume, and it communicates with iSCSI target.