CONTENTS

 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     Frame check sequence (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          
        4.3     Block interaction diagram of the data link layer       
 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     Initialization 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  –  Provision of point-to-point signalling connections    
Annex   B  –  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  –  SDL representation of the broadcast procedures    
Annex D – State transition table of the point-to-point procedures of the data link layer    
        D.2     Key to the state transition table      
Annex  E  –  Protocol Implementation Conference Statement (PICS) to Recommendation Q.921 for Basic Rate (User-side)    
        E.1     General  
        E.2     Abbreviations and special symbols 
        E.3     Instructions for completing for PICS Proforma       
        E.4     Global statement of conformance   
        E.5     Protocol Capabilities (PC) 
        E.6     Frames – Protocol Data Units (FR)           
        E.7     System parameters (SP)    
Appendix  I  –  Retransmission of REJ response frames    
        I.1     Introduction
        I.2     Procedure  
Appendix  II  –  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           
       II.3     Preferred management actions        
Appendix  III  –  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  –  Automatic negotiation of data link layer parameters    
       IV.1     General 
       IV.2     Automatic negotiation of data link layer parameter values   
References