This Counter64 field tallies the bytes on the reverse direction of this bidirectional CES tunnel that were forwarded, specifically traffic the device actually transmitted out of the tunnel after policing and queuing decisions had already been applied. Because this is today's still-open 24-hour PM window, which keeps growing through the day and resets only when the daily boundary rolls over, comparing this to the matching RxAccepted counter for the same direction shows whether everything the policer let in on ingress is actually making it out the egress side, 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 today's still-running 24-hour bin this counter might climb by roughly 5.1 MB 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 forwarded volume both ways.