A digital interface protocol that is used to transfer digital audio data between professional digital audio equipment such as PCM and DAT mastering recorders, MDM recorders and other equipment. This protocol is most commonly known as AES/EBU, but IEC958 Part-4 is the actual name for it. Two channels of digital audio are carried on a single line. An XLR-type connector and a shielded cable is typically used. More recently a two-line standard has come in to play as more people are working with 24/96 material.