CONTENTS

1 Reference configurations
1.1 Customer access configuration
1.2 Network configuration
1.3 Interworking situation
2 Terminal adaption functions
2.1 Terminal adaption functions for DTEs conforming to X.1 user classes of service 3 to 6
2.2 Terminal adaption functions for DTEs conforming to X.1 user class of service 7
2.3 Terminal adaption functions for DTEs conforming to X.1 user class of service 19
2.4 Terminal adaption functions for DTEs conforming to X.1 user classes of service 1, 2, 14, 15, 16, 17 and 18
3 Test loops
3.1 Test loop reference configuration
3.2 Test loop characteristics
3.3 Loop activation/deactivation mechanism
3.4 Coding of activation/deactivation control message
Annex A SDL diagrams
A.1 General
A.2 Some remarks about the formal description
Appendix I Universal terminal adaptor
I.1 User rate identification
I.3 Loss of alignment/recovery
I.4 Ready for data alignment
Appendix II Inslot identification of intermediate bit rate
II.1 Identification of intermediate rate
II.2 Restitution of the intermediate rate
II.3 User rate identification