This carries, within a pseudowire-related trap, the unique table index of the specific pseudowire the notification concerns, letting a receiving management system correlate the trap directly back to that pseudowire's full row of attributes in the PW table. Because a device can host many pseudowires, this index is essential for a trap receiver to know precisely which one triggered the alert rather than just 'a pseudowire somewhere changed state.' A trap carrying PW index 88 tells the NMS to look up entry 88 in the pseudowire table to pull its name, customer, and current state for the alert.