�1���� Functional
description of the signalling system
������� 1.1���� General
������� 1.2���� Data User Part
������� 1.3���� Message Transfer Part
�2����
General function of data signalling
messages, signals, indicators, codes and conditions
������� 2.1���� Signalling messages
������� 2.2���� Service information
������� 2.3���� Signalling information transferred in the signalling messages
������� 2.4���� Data channel signalling condition
�3����
Formats and codes
������� 3.1���� Basic format characteristics
������� 3.2���� Label
������� 3.3���� Formats and codes for call and circuit related messages
������� 3.4���� Formats and codes for facility registration and cancellation
messages
������� 3.5���� Data channel signalling conditions
�4����
Basic call control and signalling
procedures
������� 4.1���� General
������� 4.2���� Overall call set-up and clear-down procedures
������� 4.3���� Normal switching procedures
������� 4.4���� Detailed signalling procedures under normal conditions
������� 4.5���� Call handling in abnormal conditions
�5����
Additional call control and
signalling procedures
������� 5.1���� General
������� 5.2���� Closed user group facilities
������� 5.3���� Bilateral closed user group facilities
������� 5.4���� Calling line identification
������� 5.5���� Called line identification
������� 5.6���� Redirection of calls
������� 5.7���� Connect when free and waiting allowed
������� 5.8���� Reverse charging and reverse charge acceptance
������� 5.9���� Manual answer
������ 5.10���� RPOA selection
������ 5.11���� Network identification utilities
�6����
Signalling performance and traffic
characteristics in data applications
������� 6.1���� Signalling reliability
������� 6.2��� �Message transfer times
������� 6.3���� Data signalling traffic models
Appendix I - Examples of signalling
traffic characteristics