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• CCITT Rec. T.90 (11/1988) – CHARACTERISTICS AND PROTOCOLS FOR TERMINALS FOR TELEMATIC SERVICES IN ISDN
• CONTENTS
• 1 Scope
  • 1.1 General
  • 1.2 Use of bearer capability
  • 1.3 Protocol architecture
• 2 ISDN circuit-switched mode (DTE-DTE communication)
  • 2.1 Protocol set
  • 2.2 Application rules for B-channel circuit-switched mode
    • 2.2.1 Layer 1 physical layer interface characteristics
    • 2.2.2 Connection control phase
    • 2.2.3 Layer 2 information transfer phase
    • 2.2.4 Layer 3 - connection control phase
    • 2.2.5 Layer 3 - virtual connection control and information transfer
    • 2.2.6 Layer 3 - packet size (NPDU block length)
• 3 ISDN packet switched mode (DTE-DCE communication)
  • 3.1 Protocol set
  • 3.2 Application rules for B-channel packet-switched mode
    • 3.2.1 Layer 1 - physical layer interface characteristics
    • 3.2.2 Layer 2 - link layer procedure
    • 3.2.3 Layer 3 - network layer procedure
• 4 Provision of the OSI network service (OSI NS)
  • 4.1 Rationale for considering the OSI NS
  • 4.2 Architecture/available ISO Standards and CCITT Recommendations
  • 4.3 Requirements for the OSI NS
    • 4.3.1 Minimum requirements for the OSI NS
    • 4.3.2 Minimum functionality when receiving a call from a system using the OSI NS
• 5 Additional X.25 optional user facilities
  • 5.1 Categories of additional functionalities (see Note)
  • 5.2 Functionalities
• 6 Interactions between the D-channel and B-channel
• 7 Supplementary services
• 8 Terminal response time
• 9 Synchronization
• 10 Higher layer protocols
  • 10.1 Transport layer
• ANNEX A – Procedures for connection establishment, connection release and information transfer
• A.1 B–channel circuit–switched mode
• A.2 Packet–switched mode
• APPENDIX I – Consideration of incoming calls for facsimile terminals from networks without HLC provision
• APPENDIX II – Optional usage of T.70 NL protocol
• II.1 Information transfer phase
• II.2 Information transfer phase
• APPENDIX III – Service definitions and state transition diagrams for the data link layer within the B-channel (CS-mode)
• III.1 Service definitions
• III.2 State transition disgrams HDLC
• III.3 Summary of frame definitions
• APPENDIX IV – Possible model for telematic endsystems taking into account the D-channel/B-channel coordination function