This Counter64 field tallies the bytes on the reverse direction of this bidirectional CES tunnel that were yellow on ingress, specifically traffic that arrived over the tunnel's committed rate but within its excess rate, so the policer marked it yellow (discard-eligible) instead of admitting it cleanly or dropping it outright. Because this TotalStats row has neither a clear-time nor a Duration/State field — it is the true lifetime, never-reset total for this PM instance since it was provisioned, a climbing count here is an early-warning sign that this direction of the tunnel is running over its committed bandwidth profile even though the traffic, for now, is still getting through, and tracking it separately per direction (forward vs. reverse) lets you tell whether a problem is one-sided rather than affecting the whole tunnel. For instance, over the lifetime of this PM instance this counter might climb by roughly 58 KB of reverse-direction traffic — if the matching counter for the forward direction stays far lower (or far higher) than this one, that directional imbalance is itself the diagnostic clue, since a healthy bidirectional tunnel would normally carry fairly similar yellow volume both ways.