This OID captures the high-order 32 bits of the lifetime odometer counter for cells received on an ATM SVC VCC in direction 'B', preserving cumulative inbound usage across connection resets and restarts. Network engineers monitor this to ensure that bidirectional links maintain balanced usage patterns over time and to catch persistent one-way failures that would be missed if only session counters were checked. A significant imbalance between the direction A and direction B odometer counters over weeks of operation suggests the link is carrying asymmetric traffic or one direction has intermittent failures.