This read-only Counter32, in bytes, counts the total number of output bytes sent through the VPDN tunnel, though this object is noted as superseded by the 64-bit cvpdnTunnelBytesOut64 to avoid wraparound on high-throughput tunnels. Administrators use it to monitor outbound byte volume for bandwidth and capacity tracking, being aware that on very high-throughput tunnels this 32-bit counter can wrap and should be supplemented by its 64-bit counterpart. For example, on a tunnel carrying sustained high-bandwidth traffic, an admin monitoring dashboards should prefer cvpdnTunnelBytesOut64 to avoid misreading wrapped counter values as a drop in traffic.