A read-only counter tracking how many times the standard ifOutOctets counter for this interface has wrapped around from its 32-bit maximum back to zero. This lets an admin or monitoring script compute true cumulative outbound byte totals on high-throughput interfaces where the 32-bit ifOutOctets counter alone would wrap too frequently to track accurately. On a heavily loaded gigabit interface, this rollover count paired with ifOutOctets lets a monitoring tool calculate true total bytes transmitted without misinterpreting a counter wraparound as lost traffic.