CONTENTS

�1���� Introduction
�2���� Unsuccessful calls due to signalling malfunction
�3���� Unavailability of a signalling route set
�4���� Labelling potential
�5���� Cross-office transfer time
������� 5.1���� Functional reference points and transfer time components
������� 5.2���� Definitions
������� 5.3���� Queueing delay
������� 5.4���� Estimates for message transfer time
������� 5.5���� Answer delay
������� 5.6���� Delays due to data base queries
References