This read-only counter tracks the number of CLNP segments received that needed to be reassembled at this entity because the original PDU had been fragmented in transit. An admin uses this to gauge how much of the incoming traffic arrives fragmented, which matters because reassembly consumes buffer memory and CPU relative to unfragmented traffic. For example, an unusually high count here relative to total received PDUs might prompt the admin to investigate whether an upstream device is unnecessarily fragmenting CLNP packets that could otherwise be sent whole.