This read-write TxDeiAction object specifies the action taken on the transmit Drop Eligibility Indicator for frames egressing an Ethernet Network Port. Admins configure it as part of the drop-eligibility marking scheme to control whether the DEI bit is set, cleared, or passed through unchanged on outgoing frames, affecting how downstream equipment treats those frames under congestion. For example, an admin wanting all excess (yellow) traffic clearly marked drop-eligible on egress would configure cmEthernetNetPortTxDeiAction to set the DEI bit for that traffic rather than leaving it unmarked.