CCITT Rec. Q.931 (11/1988) – ISDN USER-NETWORK INTERFACE LAYER 3 SPECIFICATION FOR BASIC CALL CONTROL
1 General
1.1 Scope of the Recommendation
1.2 Application to interface structures
2 Overview of call control
2.1 Circuit switched calls
2.2 Packet-mode access connections
2.3 Temporary signalling connections
2.4 States associated with the global call reference
3 Message functional definitions and content
3.1 Messages for circuit mode connection control
3.2 Messages for packet-mode access connection control
3.3 Messages for user-to-user signalling not associated with circuit switched calls
3.4 Messages used with the global call reference
4 General message format and information elements coding
4.1 Overview
4.2 Protocol discriminator
4.3 Call reference
4.4 Message type
4.5 Other information elements
4.6 Supplementary services information elements
4.7 Information elements for packet communications
5 Circuit-switched call control procedures
5.1 Call establishment at the originating interface
5.2 Call establishment at the destination interface
5.3 Call clearing
5.4 In-band tones and announcements
5.5 Restart procedure
5.6 Call rearrangements
5.7 Call collisions
5.8 Handling of error conditions
5.9 User notification procedure
6 Packet communications procedures
6.1 Outgoing access
6.2 Incoming access
6.3 Virtual call establishment and release
6.4 Call clearing
6.5 Access collision
7 User-to-user signalling procedures
7.1 Procedures for user-to-user signalling associated with circuit-switched calls
7.2 Procedures for user-to-user signalling not associated with circuit-switched calls
8 Application of circuit-switched supplementary services to terminals using stimulus procedures
9 List of system parameters
9.1 Timers in the network side
9.2 Timers in the user side
ANNEX A (to Recommendation Q.931) User side and network side SDL diagrams
ANNEX B (to Recommendation Q.931) Compatibility checking
B.1 Introduction
B.2 Calling side compatibility checking
B.3 Called side compatibility checking
B.4 Interworking with existing networks
ANNEX C (to Recommendation Q.931) Transit network selection
C.1 Selection not supported
C.2 Selection supported
ANNEX D (to Recommendation Q.931) Extensions for symmetric call operation
D.1 Additional message handling
D.2 Timers for call establishment
D.3 Call collisions
ANNEX E (to Recommendation Q.931) Network specific facility selection
E.1 Default provider
E.2 Routing not supported
E.3 Routing supported
ANNEX F (to Recommendation Q.931) D-channel backup procedures
F.0 Foreword
F.1 General
F.2 D-channel backup procedure
ANNEX G (to Recommendation Q.931) Cause definitions
G.1 Normal class
G.2 Resource unavailable class
G.3 Service or option not available class
G.4 Service or option not implemented class
G.5 Invalid message (e.g., parameter out of range) class
G.6 Protocol error (e.g., unknown message) class
G.7 Interworking class
ANNEX H (to Recommendation Q.931) Examples of information elements coding
H.1 Bearer capability information element
H.2 Channel identification information element
H.3 Called/calling party sub-address information element
ANNEX I (to Recommendation Q.931) Use of progress indicators
ANNEX J (to Recommendation Q.931) Examples of cause value and location for busy condition
ANNEX K (to Recommendation Q.931) Message segmentation procedures
K.1 Introduction
K.2 Message segmentation
K.3 Reassembly of segmented messages
ANNEX L (to Recommendation Q.931) Llow layer information coding principles
L.1 Purpose
L.2 Principles
L.3 Information classification
L.4 Scenarios outside the scope of ISDN standardization
ANNEX M (to Recommendation Q.931) Low layer compatibility negotiation
M.1 General
M.2 Low layer compatibility notification to the called user
M.3 Low layer compatibility negotiation between users
M.4 Low layer compatibility negotiation options
ANNEX N (to Recommendation Q.931) Procedures for establishment of bearer connection prior to call acceptance
N.1 General
N.2 Procedures
ANNEX O (to Recommendation Q.931) Optional procedures for bearer service change
APPENDIX I (to Recommendation Q.931) Usage of cause values
APPENDIX II (to Recommendation Q.931) Example message flow diagrams and example conditions for cause mapping
II.1 Example message flow diagrams
II.2 Example conditions for cause mapping
APPENDIX III (to Recommendation Q.931) Summary of assigned information element identifier and message type code p...
ACRONYMS USED IN RECOMMENDATION Q.931
References