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• CCITT Rec. X.30 (11/1988) – SUPPORT OF X.21, X.21 bis AND X.20 bis BASED DATA TERMINAL EQUIPMENTS (DTEs) BY AN INTEGRATED SERVICES DIGITAL ...
• 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 and 2 (asynchronous operation)
• 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
• 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
• Reference