An enhanced services display message protocol (ESDMP) facilitates display of messages in a compliant analog telephony device (ATD). An exemplary gateway device in a voice over packet (VOP) network can activate enhanced services in a compliant ATD using the ESDMP and includes a controller and first and second interfaces. One of the interfaces can transmit and receive communications over a VOP network. The other interface can transmit and receive voice band message data modulated according to a frequency shift keying (FSK) protocol. The ESDMP can be used to configure the gateway to activate features supported by the ATD, to update call state information and to display feature state information.