ETS 300 125 : 20001

Foreword
Scope
PART 1: Application of CCITT Recommendation Q.920(I.440)
ISDN user-network interface data link layer - General
aspects
1 General
2 Concepts and terminology
3 Overview description of LAPD functions and procedures
  3.1 General
  3.2 Unacknowledged operation
  3.3 Acknowledged operation
  3.4 Establishment of information transfer modes
4 Service characteristics
  4.1 General
  4.2 Services provided to layer
  4.3 Services provided to layer management
  4.4 Administrative services
  4.5 Model of the data link service:
  4.6 Services required from the physical layer
5 Data link layer - Management structure
  5.1 Data link procedure
  5.2 Multiplex procedure
  5.3 Structure of the data link procedure
  5.4 Additions for European networks
PART 2: Application of CCITT Recommendation Q.921(I.441)
ISDN user-network interface - Data link layer
specification
1 General
2 Frame structure for peer-to-peer communication
  2.1 General
  2.2 Flag sequence
  2.3 Address field
  2.4 Control field
  2.5 Information field
  2.6 Transparency
  2.7 FCS field
  2.8 Format convention
  2.9 Invalid frames
  2.10 Frame abort
3 Elements of procedures and formats of fields for data
  link layer peer-to-peer communication
  3.1 General
  3.2 Address field format
  3.3 Address field variables
  3.4 Control field formats
  3.5 Control field parameters and associated state
      variables
  3.6 Frame types
4 Elements for layer-to-layer communication
  4.1 General
  4.2 Primitive procedures
5 Definition of the peer-to-peer procedures of the data
  link layer
  5.1 Procedure for the use of the P/F bit
  5.2 Procedures for unacknowledged information
      transfer
  5.3 Terminal Endpoint Identifier (TEI) management
      procedures
  5.4 Automatic negotiation of data link layer
      parameters
  5.5 Procedures for establishment and release of
      multiple frame operation
  5.6 Procedures for information transfer in multiple
      frame operation
  5.7 Re-establishment of multiple frame operation
  5.8 Exception condition reporting and recovery
  5.9 List of system parameters
  5.10 Data link layer monitor function
Annex A (to Recommendation Q.921) Provision of
         point-to-point signalling connections
Annex B (to Recommendation Q.921) SDL for
         point-to-point procedures
  B.1 General
  B.2 An overview of the states of the point-to-point
      data link layer entity
  B.3 Cover notes
  B.4 The use of queues
  B.5 SDL representation
Annex C (to Recommendation Q.921) An SDL representation
         of the broadcast procedures of the data link
         layer
Annex D (to Recommendation Q.921) State transition
         table of the point-to-point procedures of the
         data link layer
  D.1 State transition table
  D.2 Key to the state transition table
Appendix I (to Recommendation Q.921) Retransmission of
            REJ response frames
  I.1 Introduction
  I.2 Procedure
Appendix II (to Recommendation Q.921) Occurrence of
             MDL-ERROR-INDICATION within the basic
             states and actions to be taken by the
             management entity
  II.1 Introduction
  II.2 Layout of table II-1/Q
  II.3 Preferred management actions
Appendix III (to Recommendation Q.921) Optional basic
              access deactivation procedures
  III.1 Introduction
  III.2 Description of the conceptual model
  III.3 Deactivation procedure with
        MPH-DEACTIVATE-INDICATION
  III.4 Deactivation procedure without
        MPH-DEACTIVATE-INDICATION
Appendix IV (to Recommendation Q.921) Automatic
             negotiation of data link layer parameters
  IV.1 General
  IV.2 Parameter initialisation
  IV.3 Internal parameter initialisation
  IV.4 Automatic notification of data link layer
       parameter values
History

Specifies the user-network interface data link layer of the pan-European Integrated Services Digital Network (ISDN) as provided by European public telecommunication operators at the T reference point or coincident S and T reference point.