CONTENTS

�1���� Introduction
�2���� Loss (a-b) to avoid instability during set-up, clear-down and changes in a connection
�3���� Unweighted loss (a-b) on established connections
�4���� Echo loss (a-b) on established connections
Annex A � Measurement of stability loss (a-b) and echo loss (a-b)
Annex B � Explanation of terms associated with the path a-t-b
������� B.1���� Return loss
������� B.2���� Balance return loss
������� B.3���� Transmission loss of the path a-t-b
������� B.4���� Stability and echo losses
������� B.5���� Overall loudness rating of the echo path (talker echo loudness rating, TELR)
������� B.6���� Summary of useful terms
References