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