1
Scope
2 References
3 Abbreviations
4 Signalling rates
4.1 Data signalling rates
4.2 Signalling rates on line
5 Differentiation between user and
network data signals
5.1 Scrambler
5.2 Descrambler
6
Interfaces
6.1 V.24-type interface [3]
6.1.1 List of interchange circuits
6.1.2 Electrical characteristics
6.1.3 Operational requirements
6.2 X.24-type interface [7]
6.2.1 List of interchange circuits
6.2.2 Electrical characteristics
6.2.3 Operational requirements
7 Start-up procedure
8 Testing facilities
8.1 Test loops
8.1.1 Instigation of remote loop 2/2b
8.1.2 Instigation of the type-3 loop
8.2 Self tests
8.2.1 Self test with the type-3 loop
8.2.2 Self test with remote loop 2/2b
9 Multiplexing
10 Internal management
Appendix I – Functional block diagram
Appendix II – Connection schematics
Appendix III – Example of implementation of the
transmission unit
III.1 General
III.2 Physical model of the line
transmission system
III.3 Functional description of the DCE
III.4 Functions of TU functional block
III.4.1 Data channels
III.4.2 DCE management channel
III.4.3 Bit timing
III.4.4 Octet timing
III.4.5 Frame alignment
III.4.6 Activation
III.4.7 Deactivation
III.4.8 Power feeding
III.4.9 Maintenance
III.5 Requirements for a line
transmission system using 2B1Q line code
III.5.1 Line code
III.5.2 Line modulation rate
III.5.3 Clock tolerance
III.5.4 Frame structure
III.5.5 Frame and multiframe words
III.5.6 Frame offset between slave TU and master TU
III.5.7 CL channel
III.6 DCE management channel
III.6.1 Protocol and procedure
III.6.2 Functions provided
III.7 Equipment management function
III.7.1 General
III.7.2 Specific functions of the equipment management function with TU working
in slave mode
III.7.3 Specific functions of equipment management
function with TU working in master mode