This Recommendation applies to all echo cancellers specified in accordance with Recommendation G.165 [1], which are located either in international or national networks and which are used for international calls.
ITU-T M.665 SPANISH-1988 Referenced Document
ITU-T G.165 Echo Cancellers Study Group XV; 31 PP*, 1993-01-01 Update
ITU-T O.22 CCITT Automatic Transmission Measuring and Signalling Testing Equipment ATME No. 2 - Specifications of Measuring Equipment (Study Group IV) 35 pp*, 1992-01-01 Update
ITU-T O.27 In-Station Echo Canceller Test Equipment