This object gives a textual description of the layered interface stack, including the IP interface, the frame relay interface, and the underlying device interface, associated with this entry. An admin reads this to understand how the frame relay interface is layered on top of the physical device interface when troubleshooting a multi-layer interface configuration. For example, xfrArpIfStack might read something like ip0 over fr1 over serial2, letting the admin trace the mapping down to the physical serial port.