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• CCITT Rec. Q.83.2 (1988) – CALL COMPLETION SUPPLEMENTARY SERVICES – CALL HOLD
• 2 Call hold
  • 2.1 Introduction
    • 2.1.1 Definition
  • 2.2 Definition of functional model
    • 2.2.1 Functional model description
    • 2.2.2 Relationship to basic service
  • 2.3 Information flow description
    • 2.3.1 Information flow diagram for successful operation
    • 2.3.2 Definition of individual information flows
  • 2.4 Functional entity actions
  • 2.5 SDL diagrams for functional entities
  • 2.6 Network physical allocation scenarios