CONTENTS

 1     Introduction
        1.1     Scope and field of application
 2     Type of configuration
        2.1     Point-to-point
        2.2     Location of interfaces
 3     Functional characteristics
        3.1     Summary of functions (layer 1)
        3.2     Interchange circuits
        3.3     Activation/deactivation
        3.4     Operational functions
 4     Interface at 1544 kbit/s
        4.1     Electrical characteristics
        4.2     Frame structure
        4.3     Timing considerations
        4.4     Time slot assignment
        4.5     Jitter, wander and phase transients
        4.6     Interface procedures
        4.7     Maintenance
 5     Interface at 2048 kbit/s
        5.1     Electrical characteristics
        5.2     Frame structure
        5.3     Timing considerations
        5.4     Jitter
        5.5     Tolerable longitudinal voltage
        5.6     Output signal balance
        5.7     Impedance towards ground
        5.8     Interface procedures
        5.9     Maintenance at the interface
 6     Connector
 7     Interface wiring
 8     Power feeding
        8.1     Provision of power
        8.2     Power Consumption
        8.3     Voltage range
        8.4     Protection
Annex A – Time slot assignment for interfaces having only H0-channels
        A.1     1544 kbit/s interface
        A.2     2048 kbit/s interface
Annex B – Time slot assignment for 2048 kbit/s interfaces having an H11-channel
Appendix I – Pulse mask for interface at 1544 kbit/s