This counts received PW packets whose header or payload size didn't match what the CESoP encapsulation expected, so they could not be interpreted as valid TDM payload. Malformed packets on this pseudowire point to an interoperability or MTU/fragmentation mismatch with the far-end PW endpoint rather than ordinary network loss, since a healthy peer running compatible CESoP settings should never emit them -- and this specific object covers a closed 15-minute history bin -- a fixed, final count for one completed interval rather than something still changing. For example, over that completed 15-minute bin, this pseudowire might show this counter at 2 -- a concrete count the admin can trend against neighboring bins to judge whether the condition it reflects is worsening.