1
Introduction
1.1 General characteristics of the signalling network functions
1.2 Signalling message handling
1.3 Signalling network management
2
Signalling message handling
2.1 General
2.2 Routing label
2.3 Message routing function
2.3.4 Handling of level 3 messages
2.3.5 Handling of messages under signalling
link congestion
2.4 Message discrimination and distribution functions
3
Signalling network management
3.1 General
3.2 Status of signalling links
3.2.2 Signalling link failure
3.2.3 Signalling link restoration
3.2.4 Signalling link deactivation
3.2.5 Signalling link activation
3.2.6 Signalling link blocking
3.2.7 Signalling link unblocking
3.2.8 Signalling link inhibiting
3.2.9 Signalling link uninhibiting
3.3 Procedures used in connection with link status changes
3.3.1 Signalling link failed
3.3.2 Signalling link restored
3.3.3 Signalling link deactivated
3.3.4 Signalling link activated
3.3.5 Signalling link blocked
3.3.6 Signalling link unblocked
3.3.7 Signalling link inhibited
3.3.8 Signalling
link uninhibited
3.4 Status of signalling routes
3.4.1 Signalling route unavailability
3.4.2 Signalling route availability
3.4.3 Signalling route restricted1
3.5 Procedures used in connection with route status changes
3.5.1 Signalling route unavailable
3.5.2 Signalling route available
3.5.3 Signalling route restricted1
3.6 Status of
signalling points
3.6.1 Signalling point unavailability
3.6.2 Signalling point availability
3.7 Procedures used in connection with point status changes
3.7.1 Signalling point unavailable
3.7.2 Signalling point available
3.8 Signalling network congestion
3.8.1 General
3.8.2 Congestion status of signalling links
3.8.3 Procedures used in connection with link
congestion status changes
3.8.4 Congestion status of signalling route
sets
3.8.5 Procedures used in connection with route
set congestion status changes
4
Signalling traffic management
4.1 General
4.2 Normal routing situation
4.3 Signalling link unavailability
4.4 Signalling link availability
4.5 Signalling route unavailability
4.6 Signalling route availability
4.7 Signalling route restriction1
4.8 Signalling point availability
5
Changeover
5.1 General
5.2 Network configurations for changeover
5.3 Changeover initiation and actions
5.4 Buffer
updating procedure
5.5 Retrieval and diversion of traffic
5.6 Emergency changeover procedures
5.7 Procedures in abnormal conditions
6
Changeback
6.1 General
6.2 Changeback initiation and actions
6.3 Sequence control procedure
6.4 Time-controlled diversion procedure
6.5 Procedures in abnormal conditions
7
Forced rerouting
7.1 General
7.2 Forced rerouting initiation and actions
8
Controlled rerouting
8.1 General
8.2 Controlled rerouting initiation and actions
9
MTP restart
9.1 General
9.2 Actions in a signalling point whose MTP is restarting
9.3 Actions in a signalling
point X, adjacent to a signalling point Y whose MTP restarts
9.4 Short term isolations
9.5 TRA messages and timer T19
9.6 General rules
9.7 Sequence diagrams
9.7.1 SP with restarting MTP according to
subclause 9.2
9.7.2 Actions in SP X adjacent to SP Y whose
MTP restarts according to subclause 9.3
10 Management inhibiting
10.1 General
10.2 Inhibiting initiation and actions
10.3 Uninhibiting initiation and actions
10.3.1 Management-initiated uninhibiting
10.3.2 Signalling routing control initiated
uninhibiting
10.4 Receipt of unexpected management inhibition messages
10.5 Management inhibited link status and processor recovery
10.6 Inhibit test procedure
11 Signalling traffic flow control
11.1 General
11.2 Flow control indications
11.2.1 Signalling route set unavailability
11.2.2 Signalling route set availability
11.2.3 Signalling route set congestion
(International signalling network)
11.2.4 Signalling route set congestion (National
option with congestion priorities)
11.2.5 Signalling route set congestion (National
options without congestion priorities)
11.2.6 Signalling point/signalling transfer
point congestion
11.2.7 User Part availability control
11.2.8 User Part congestion
12 Signalling link management
12.1 General
12.2 Basic signalling link management procedures
12.2.1 Signalling link activation
12.2.2 Signalling link restoration
12.2.3 Signalling link deactivation
12.2.4 Link set activation
12.3 Signalling link management procedures based on automatic
allocation of signalling terminals
12.3.1 Signalling link activation
12.3.2 Signalling link restoration
12.3.3 Signalling link deactivation
12.3.4 Link set activation
12.4 Signalling link management procedures based on automatic
allocation of signalling data links and signalling terminals
12.4.1 Signalling link activation
12.4.2 Signalling link restoration
12.4.3 Signalling link deactivation
12.4.4 Link set activation
12.5 Automatic allocation of signalling terminals
12.6 Automatic allocation of signalling data links
12.7 Different signalling link management procedures at the two
ends of a link set
13 Signalling route management
13.1 General
13.2 Transfer-prohibited
13.3 Transfer-allowed
13.4 Transfer-restricted (National option)
13.5 Signalling-route-set-test
13.6 Transfer-controlled
(International network)
13.7 Transfer-controlled (National option with congestion
priorities)
13.8 Transfer-controlled (National option without congestion
priorities)
13.9 Signalling-route-set-congestion-test (National Option)
14 Common characteristics of message
signal unit formats
14.1 General
14.2 Service information octet
14.2.1 Service indicator
14.2.2 Sub-service field
14.3 Label
15 Formats and codes of signalling
network management messages
15.1 General
15.2 Label
15.3 Heading code (H0)
15.4 Changeover message
15.5 Changeback message
15.6 Emergency changeover
message
15.7 Transfer-prohibited message
15.8 Transfer-allowed message
15.9 Transfer-restricted message (national option)
15.10 Signalling-route-set-test message
15.11 Management inhibit message
15.12 Traffic restart allowed message
15.13 Signalling-data-link-connection-order message
15.14 Signalling-data-link-connection-acknowledgement message
15.15 Transfer-controlled message
15.16 Signalling-route-set-congestion-test message (national option)
15.17 User Part unavailable message
16 State transition diagrams,
abbreviations and timers
16.1 General
16.2 Drafting conventions
16.2.5 Notations for national operations
16.3 Signalling message handling
16.4 Signalling traffic management
16.5 Signalling link management
16.6 Signalling route management
16.7 Abbreviations used in Figures 23 onwards
16.8 Timers and timer values