DIN ETS 300125:1992-05

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 3
   4.3 Services provided to layer management
   4.4 Administrative services
   4.5 Model of the date 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 date link procedure
   5.4 Additions for European networks
References (used in Q.920)
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 Flak 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 date
   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 date 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
   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.9211: Provision of point-to-point
         signalling connections
Annex B (to Recommendation Q.921): SDL for point-to-point procedures
B.1 General
8.2 An overview of the states of the point-to-point date 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 a 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
D.2.1 Definition of a cell of the state transition fable
D.2.2 Key to the contents of a cell
Appendix I (to Recommendation Q.921): Retransmission of REJ response
            frames
1.1 Introduction
1.2 Procedure
Appendix II (to Recommendation Q.921): Occurrence of MDL-ERROR-INDICATION
             within the states and actions to be taken by
             the management entity
11.1 Introduction
11.2 Layout of fable II-1/Q.921
11.3 Preferred management actions
Appendix III (to Recommendation Q.921): Optional basic access deactivation
     procedures
111.1 Introduction
111.2 Description of the conceptual model
111.3 Deactivation procedure with MPH-DEACTIVATE-INDICATION
111.4 Deactivation procedure without MPH-DEACTIVATE-INDICATION
Appendix IV (to Recommendation 6.921): Automatic negotiation of date link
     layer Parameters
IV.1 General
IV.2 Parameter initialisation
IV.3 Internal Parameter initialisation
IV.4 Automatic notification of date link layer Parameter values
Abbreviations and acronyms used in Recommendation Q.921 (I.441)
References (used in Q.921)

This Standard 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 (as defined in CCITT Recommendation 1.411 [13] by means of Digital Subscriber Signalling System No. 1 (DSS1).