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 Stats row carries no Duration or State field at all, unlike the Curr/History bins — it is a running tally since the last manual clear rather than a fixed-length interval, 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 period since the last manual clear this counter might climb by roughly 53 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.