IRec. ITU-T G.131/Q.42 (11/1988) � STABILITY AND ECHO
1 Stability of telephone transmission
2 Limitation of echoes
    2.1 Transmission loss adjustment
    2.2 Echo control devices
    2.3 Rules governing the limitation of echoes
    2.4 Insertion of echo control devices in a connection
    2.5 Speech processing devices
ANNEX A � Application of Recommendation G.131, � 2
A.1 Full analogue connections (Figure A-1/G.131)
A.2 Fully digital connections (Figure A-2/G.131)
A.3 Mixed analogue/digital connections
References