CONTENTS

 1     General
 2     Characteristics of interfaces
        2.1     Characteristics common to all 4-wire analogue interfaces
                  2.1.1     Exchange impedance
                  2.1.2     Impedance unbalance about earth
                  2.1.3     Relative levels
        2.2     Characteristics of interface C₁₁
                  2.2.1     Values of nominal levels
        2.3     Characteristics of interface C₁₂
                  2.3.1     Values of nominal levels
        2.4     Characteristics of interface C₁₃
                  2.4.1     Values of nominal levels
 3     Characteristics of half connections
        3.1     Characteristics common to all 4-wire analogue interfaces
                  3.1.1     Transmission loss
                  3.1.2     Group delay
                  3.1.3     Noise
                  3.1.4     Crosstalk
                  3.1.5     Total distortion including quantizing distortion
                  3.1.6     Discrimination against out-of-band signals applied to the input interface
                  3.1.7     Spurious out-of-band signals received at the output interface
        3.2     Characteristics for interface C₁₁
                  3.2.1     Nominal value of transmission loss
        3.3     Characteristics for interface C₁₂
                  3.3.1     Nominal value of transmission loss
        3.4     Characteristics for interface C₁₃
                  3.4.1     Nominal value of transmission loss