Multiplexer to transmitter interface protocol. A method for a data interface protocol is provided that includes receiving a first packet stream having at least one overhead information symbol (OIS) group and at least one multicast logical channel (MLC) group, and mapping each OIS group to an OIS descriptor packet and at least one OIS payload packet. The method also includes mapping each MLC group to an MLC descriptor packet and at least one MLC payload packet, and outputting the OIS descriptor, OIS payload, MLC descriptor, and MLC payload packets in a second packet stream. An apparatus includes input logic to receive the first packet stream, processing logic to map each OIS group to an OIS descriptor packet an OIS payload packet, and each MLC group to an MLC descriptor packet and an MLC payload packet, and output logic to output the mapped packets in a second packet stream.