ITU-T Rec. Q.552 (1988)
1 General
2 Characteristics of interfaces
2.1 Characteristics of interface C2
2.2 Characteristics of interface Z
3 Characteristics of half-connections
3.1 Characteristics common to all 2-wire analogue interfaces
3.2 Characteristics of interface C2
3.3 Characteristics of interface Z
ANNEX A – Example of a longitudinal interference coupling network