CONTENTS

 1     Scope 
 2     References 
 3     Reference architectures for PSTN-IP-PSTN voice service           
4.     QoS framework  
 5     QoS categorization and applicability         
        5.1     Connection quality 
        5.2     Call clarity 
 6     IP network impacts          
 7     QoS measurement and management of PSTN-IP-PSTN architecture       
 8     Further study