Abstract: An improved mechanism is provided for storage, recovery, and analysis of network traffic data, without requiring prohibitive amounts of storage space. Network traffic data is recorded in a sliding buffer. In normal operation, after some period of time, the oldest data in the buffer is deleted, yielding more storage space for more recent data. In response to a trigger event, such as any detected problem, attack, or similar incident, relevant pre-event and post-event data is retained for analysis.

Abstract: A radiator fan shroud (100) is disclosed that is adapted to be attached to a vehicle radiator (96)—for example, the radiator of a Class 8 truck. The fan shroud includes a peripheral cover portion (112) and a ring assembly (102) that encloses the blades of the engine-driven radiator fan (88). The ring assembly may be formed integrally with the peripheral cover portion or may include a separable ring extension (120). The ring assembly includes a plurality of ports (104) defined by vanes (106) at the rearward portion of the ring assembly. The ports are selectively positioned to manage the airflow in the engine compartment, directing the airflow towards selected locations. The vanes may be fluted. The fan shroud may be formed from two or more pieces that cooperatively form the fan shroud, to facilitate installation and maintenance of the fan shroud.