CONTENTS

 1     Scope
 2     Normative references
 3     Definitions, symbols and abbreviations
        3.1     Definitions
        3.2     Symbols and abbreviations
 4     Electrical and physical interface requirements
 5     Procedural interface requirements
        5.1     Link control requirements and procedures
                  5.1.1     Link-ID verification
                  5.1.2     Link blocking
 6     Services and architecture aspects and requirements
        6.1     On-demand services
                  6.1.1     PSTN
                  6.1.2     ISDN Basic Access (ISDN-BA)
                  6.1.3     ISDN Primary Rate Access (ISDN-PRA)
        6.2     Permanent Line (PL) capability
        6.3     Semi-permanent leased line
        6.4     Permanent leased line service
 7     Control and provisioning
        7.1     Control principles
                  7.1.1     General requirements and assumptions
                  7.1.2     Control of ISDN-BA user port for the PL capability
                  7.1.3     Control of ISDN-PRA user ports when the PL capability is provided
                               7.1.3.1     Statements and assumptions
                               7.1.3.2     ISDN and PL capability
        7.2     Provisioning strategy and requirements
                  7.2.1     General    
                  7.2.2     Provisioning requirements
        7.3     Bearer Channel Connection (BCC)
        7.4     Protection
 8     Protocol architecture and multiplexing structure
        8.1     Functional description
        8.2     Protocol requirements for PSTN and ISDN
        8.3     Time slots
        8.4     Time slot allocation for physical communication channels
                  8.4.1     Data types for V5.2 C-paths
                  8.4.2     Communication paths when PSTN is provided on a V5.2 interface
                  8.4.3     Communication paths when ISDN is provided on a V5.2 interface
        8.5     Layer 2 sublayering and multiplexing on communication channels
        8.6     Layer 3 multiplexing
        8.7     Congestion control
                  8.7.1     Flow control end to end
                  8.7.2     Congestion control on the V5.2 interface
                  8.7.3     Blocking of ISDN user ports at layer 2
 9     Envelope Function sublayer of LAPV5 (LAPV5-EF)
10     Data Link sublayer of LAPV5 (LAPV5-DL)
       10.1     Frame structure for peer-to-peer communication
       10.2     Invalid frames
       10.3     Elements of procedures and formats of fields for data link sublayer peer-to-peer communication
                 10.3.1     Link address field format
                 10.3.2     Link address field variables
                              10.3.2.1     Address field extension bit (EA)
                              10.3.2.2     Command/response field bit
                              10.3.2.3     V5DLaddr      
       10.4     Definition of the peer-to-peer procedures of the data link sublayer
11     AN frame relay sublayer
12     Sublayer-to-sublayer communication and mapping function
13     General layer 3 protocol structures
       13.1     General
       13.2     Information elements that appear in every message (header)
                 13.2.1     Protocol Discriminator information element
                 13.2.2     Layer 3 Address information element
                 13.2.3     Message Type information element
       13.3     Other information elements
       13.4     Protocol message functional definition and information content
       13.5     Codesets
14     PSTN signalling protocol specification and layer 3 multiplexing
15         Control requirements and protocol
       15.1     ISDN-BA user port status indication and control
       15.2     PSTN user port status indication and control
       15.3     ISDN primary rate user port status indication and control
                 15.3.1     General aspects
                 15.3.2     Events and function elements relevant for the control of the state machines
                 15.3.3     ISDN‑PRA user port FSMs, AN (ISDN port) and LE (ISDN port)
                              15.3.3.1     Description of the states
                              15.3.3.2     Definition of port control states
                              15.3.3.3     Principles and procedures
                              15.3.3.4     ISDN port FSM at the AN
                              15.3.3.5     ISDN port FSM at the LE
                 15.3.4     Performance monitoring aspects
       15.4     Control protocol
       15.5     V5.2-re-provisioning procedures
16     Link control requirements and protocol
       16.1     2048 kbit/s layer 1 link maintenance requirements
                 16.1.1     Events and failure reports
                 16.1.2     Detection algorithm for events and signals
                 16.1.3     V5.2-interface layer 1 link FSM
                 16.1.4     Requirements and procedures for the additional functions
       16.2     Link control requirements and procedures
                 16.2.1     The link blocking and unblocking
                 16.2.2     The link identification
                 16.2.3     Events and function elements relevant for the control of the link state machines
                 16.2.4     Link control FSM, AN (link) and LE (link)
                              16.2.4.1     Description of the states
                              16.2.4.2     Definition of link control states and general coordination requirements
                              16.2.4.3     Principles and procedures
                              16.2.4.4     Link control FSM at the AN
                              16.2.4.5     Link control FSM at the LE
       16.3     Link control protocol
                 16.3.1     Link control protocol message definition and content
                              16.3.1.1     LINK CONTROL message
                              16.3.1.2     LINK CONTROL ACK message
                 16.3.2     Link control protocol information element definition, structure and coding
                              16.3.2.1     Layer 3 address information element
                              16.3.2.2     Link control function information element
                 16.3.3     Definitions of the link control protocol states
                 16.3.4     Link control protocol procedure
                              16.3.4.1     General
                              16.3.4.2     Start traffic indication
                              16.3.4.3     Stop traffic indication
                              16.3.4.4     Link control layer 3 protocol entity procedure
                 16.3.5     Handling of error conditions
                              16.3.5.1     Protocol discriminator error
                              16.3.5.2     Layer 3 address error
                              16.3.5.3     Message type error
                              16.3.5.4     Repeated information elements
                              16.3.5.5     Mandatory information element missing
                              16.3.5.6     Unrecognized information element
                              16.3.5.7     Content error of mandatory information elements
                 16.3.6     Timers for the link control protocol
                 16.3.7     AN and LE side layer 3 protocol entity state tables
17     BCC protocol elements and procedures
       17.1     General
       17.2     BCC protocol entity definition
                 17.2.1     Definition of BCC protocol states
                              17.2.1.1     BCC states in the AN
                              17.2.1.2     BCC states in the LE
                 17.2.2     Definition of BCC protocol primitives, messages and timers
       17.3     BCC protocol message definition and content
                 17.3.1     ALLOCATION message
                 17.3.2     ALLOCATION COMPLETE message
                 17.3.3     ALLOCATION REJECT message
                 17.3.4     DE-ALLOCATION message
                 17.3.5     DE-ALLOCATION COMPLETE message
                 17.3.6     DE-ALLOCATION REJECT message
                 17.3.7     AUDIT message
                 17.3.8     AUDIT COMPLETE message
                 17.3.9     AN FAULT message
                17.3.10     AN FAULT ACKNOWLEDGE message
                17.3.11     PROTOCOL ERROR message
       17.4     BCC information element definition, structure and coding
                 17.4.1     BCC Reference Number information element
                 17.4.2     Other information elements
                              17.4.2.1     User Port Identification information element
                              17.4.2.2     ISDN Port Time Slot Identification information element
                              17.4.2.3     V5-Time Slot Identification information element
                              17.4.2.4     Multi-Slot Map information element
                              17.4.2.5     Reject Cause information element
                              17.4.2.6     Protocol Error Cause information element
                              17.4.2.7     Connection Incomplete information element
       17.5     Description of the BCC protocol and the BCC procedures
                 17.5.1     General   
                 17.5.2     Bearer channel allocation – Normal procedure
                 17.5.3     Bearer channel allocation – Exceptional procedures
                              17.5.3.1     Bearer channel allocation
                              17.5.3.2     Bearer channel allocation reject
                              17.5.3.3     Bearer channel allocation abort
                              17.5.3.4     Bearer channel allocation request received for existing connection
                              17.5.3.5     Bearer channel allocation, connection override requested
                 17.5.4     Bearer channel de-allocation – Normal procedure
                 17.5.5     Bearer channel de-allocation – Exceptional procedures
                              17.5.5.1     Bearer channel de-allocation
                              17.5.5.2     Bearer channel de-allocation reject
                              17.5.5.3     Bearer channel de-allocation process message missing
                 17.5.6     Audit procedure
                 17.5.7     AN internal failure notification procedure
                 17.5.8     Handling of error conditions
                              17.5.8.1     Protocol discriminator error
                              17.5.8.2     Message type error
                              17.5.8.3     Information element out of sequence
                              17.5.8.4     Repeated information elements
                              17.5.8.5     Mandatory information element missing
                              17.5.8.6     Unrecognized information element
                              17.5.8.7     Content error of mandatory information element
                              17.5.8.8     Content error of optional information element
                              17.5.8.9     Unexpected message
                             17.5.8.10     Optional information element not allowed
       17.6     List of system parameters (timers)
       17.7     LE side and AN side state transition tables
18     Protection protocol specification
       18.1     General
                 18.1.1     Introduction
                 18.1.2     Provisioning of physical and logical C-channels
                 18.1.3     Separation of responsibilities
                 18.1.4     Management of C-channel resources after failure
                 18.1.5     Monitoring functions and detection of failures
                              18.1.5.1     Failure of a 2048 kbit/s link
                              18.1.5.2     Flag monitoring
                              18.1.5.3     Data link monitoring
                 18.1.6     Functional model for the protection protocol
       18.2     Other principles
       18.3     Protection protocol entity definition
                 18.3.1     Definition of protection protocol states
                              18.3.1.1     States in the AN
                              18.3.1.2     States in the LE
                 18.3.2     Definition of protection protocol events
       18.4     Protection protocol message definition and content
                 18.4.1     SWITCH-OVER REQ message
                 18.4.2     SWITCH-OVER COM message
                 18.4.3     OS-SWITCH-OVER COM message
                 18.4.4     SWITCH-OVER ACK message
                 18.4.5     SWITCH-OVER REJECT message
                 18.4.6     PROTOCOL ERROR message
                 18.4.7     RESET SN COM message
                 18.4.8     RESET SN ACK message
       18.5     Protection protocol information element definition, structure and coding
                 18.5.1     Logical C-channel identification information element
                 18.5.2     Sequence-number information element
                 18.5.3     Physical C-channel identification information element
                 18.5.4     Rejection Cause information element
                 18.5.5     Protocol Error Cause information element
       18.6     Protection protocol procedures
                 18.6.1     General   
                 18.6.2     Broadcast of protection protocol messages on the two data links of the primary and secondary link
                              18.6.2.1     Transmission of protection protocol messages
                              18.6.2.2     Receipt of protection protocol messages
                              18.6.2.3     Sequence number reset procedure
                 18.6.3     Standard protection switch-over procedure initiated by LE-side
                              18.6.3.1     Normal procedure
                              18.6.3.2     Exceptional procedures
                              18.6.3.3     Procedure on expiry of timer TSO1
                 18.6.4     Dedicated protection switch-over procedure initiated by OS LE
                              18.6.4.1     Normal procedure
                              18.6.4.2     Exceptional procedures
                              18.6.4.3     Procedure on expiry of timer TSO2
                 18.6.5     Protection switch-over procedure requested by AN-side
                              18.6.5.1     Normal procedure
                              18.6.5.2     Exceptional procedure – AN cannot comply with switch-over command from LE
                              18.6.5.3     Exceptional procedure – LE cannot comply with switch-over request from AN
                              18.6.5.4     Procedure on expiry of timer TSO3
                 18.6.6     Handling of error conditions
                              18.6.6.1     Protocol discriminator error
                              18.6.6.2     Message type error
                              18.6.6.3     Repeated information elements
                              18.6.6.4     Mandatory information element missing
                              18.6.6.5     Unrecognized information element
                              18.6.6.6     Content error of mandatory information element
                              18.6.6.7     Unexpected message
       18.7     List of system parameters
       18.8     AN and LE side state tables
                 18.8.1     Protection protocol FSM in the AN
                 18.8.2     Protection protocol FSM in the LE
Annex A     –      Service scenarios, architecture and functional definition of access arrangements with AN at the LE
        A.1     Conclusions on multiple V5-interface applications
        A.2     Conclusions on architecture aspects
        A.3     Implementation of QAN
        A.4     Requirements for the support of the PL capability through an ISDN basic access
        A.5     Requirements for the support of the PL capability through an ISDN primary rate access
        A.6     Assumptions and requirements for the support of semi-permanent leased lines
Annex B     –      Use of the protocol information elements for national PSTN protocols
Annex C     –      Basic requirements of the system management functions in the AN and the LE
        C.1     Procedure for the ISDN basic access continuity test
       C.11     Provisioning verification
       C.12     Re-provisioning synchronization
       C.13     System startup
       C.14     Restart procedure
       C.15     Data link activation procedure
       C.16     Data link reset
       C.17     Data link failure
       C.18     Control protocol layer 3 protection mechanism error
       C.19     Timers in the system management entity
       C.26     The treatment of BCC allocation rejections by system management
       C.27     Link control protocol layer 3 protection mechanism error
Annex D     –      Protocol architecture for PSTN and ISDN (BA and PRA) user port control
        D.1     Scope
        D.2     ISDN-BA port status control
        D.3     ISDN-PRA user port status control
        D.4     PSTN user port control
Annex E     –       Frame structures, message codepoints and addressing scheme for V5.2
Annex F     –       The concept and requirements for the upgrade of a V5.1 interface to a V5.2
Annex G     –      AN requirements for pulse dialling
Annex H     –      Layer 3 error detection procedures
Annex J     –Protection protocol – Explanatory notes and information flow
        J.1     Additional information on the principles of the protection protocol
        J.2     Information flow
Annex K     –      BCC protocol application principles
        K.1     Introduction
        K.2     Time slot usability
        K.3     Time slot allocation and de-allocation rules
        K.4     Audit procedure rules
        K.5     AN internal failure notification rules
        K.6     AN internal failure rules
        K.7     BCC protocol errors
        K.8     Arrow diagrams – Examples of BCC protocol and DSS1 coordination
        K.9     Arrow diagrams – Examples of BCC and PSTN protocol coordination
Appendix I – Bibliography