This read-only Counter, with no default value and not supported in Forum Compliant IMA, tracks the number of ACP cells that could not be transmitted on this IMA group due to a lack of buffer resources. An administrator uses this to flag internal resource starvation on the transmit control-cell path, distinct from a line-quality issue reflected in the received error counters. For example, a rising xmtAcpCellsMissed count alongside otherwise clean line-quality counters would point the operator toward a local buffering or resource problem on the card rather than a cabling issue.