1) Data exchange interface 2) Half of mxxil 3) LXXIII septupled 4) Seven-fifths of CCCLXV 5) Sixth-century date 6) Sixth-century year 7) VII x LXXIII 
Data Exchange Interface
Data Exchange Interface. ATM Forum specification, described in RFC 1483, that defines how a network device such as a bridge, router, or hub can effectively act as an FEP to an ATM network by interfacing with a special DSU that performs packet segmentation and reassembly.