HP Surestore 64 HP Surestore Director FC-64 Product Manager User's Guide - Page 234

F_Port (from the originating node port) to retransmission of that data at the switch's outgoing F_Port (to the destination N_Port). The amount of time it takes for data transmission to pass through a switching device. LIN See link incident. link Physical connection between two devices on a switched fabric. link incident Interruption to link due to loss of light or other causes. load balancing Ability to evenly distribute traffic over multiple interswitch links within a fabric. Load balancing on directors takes place automatically. logical unit number Also known as LUN. In Fibre Channel addressing, a logical unit number is a number assigned to a storage device which, in combination with the storage device's node port's world-wide name, represents a unique identifier for a logical device on a storage area network. loopback plug In a fiber optic environment, a type of duplex connector used to wrap the optical output signal of a device directly to the optical input. loopback test Test that checks attachment or control unit circuitry, without checking the mechanism itself, by returning the output of the mechanism as input. LUN See logical unit number. 218 Glossary