Rec. No.
INTRODUCTION –
General
SECTION 1 – Definitions and functions of signals
Q.400 1.1 Forward line signals
1.2 Backward line signals
1.3 Forward register signals
1.4 Backward register signals
SECTION 2 – Line
signalling, analogue version
Q.411 2.1 Line signalling code
Q.412
2.2 Clauses for exchange line signalling equipment
2.3 Clauses for transmission line signalling equipmenet
Q.414 2.3.1 Signal sender
Q.415 2.3.2 Signal receiver
Q.416
2.4 Interruption control
SECTION
3 – Line signalling, digital version
Q.421 3.1 digital line signalling code
Q.422
3.2 clauses for exchange line signalling
equipment
Q.424 3.3 protection against the effects of
faulty transmission
Q.430 3.5 conversion
between analogue and digital versions of system R2 line signalling
SECTION 4 – Interregister
signalling
Q.440 4.1 General
Q.441 4.2 Signalling code
Q.442
4.3 Pulse transmission of backward signals A-3, A-4, A-6 or A-15
4.4 Multifrequency signalling equipment
Q.450 4.4.1 General
Q.451 4.4.2 Definitions
Q.452 4.4.3 Requirements relating to transmission conditions
Q.454 4.4.4 The sending part of the multifrequency signalling equipment
Q.455 4.4.5 The receiving part of the multifrequency equipment
4.5 Range, speed and reliability of interregister signalling
Q.457 4.5.1 Range of interregister signalling
Q.458 4.5.3 Reliability of interregister signalling
Annexes to Section 4:
Annex A – Development of formulae for the power level
of signalling frequencies
Annex B – Possible method of improving protection from
interruptions
Annex C – Development of a formula for the admissible
forward transmission loss in a country of destination
SECTION 5 – Signalling
procedures
Q.460 5.1 Normal call set-up procedures for international working
Q.462 5.1.2 Signalling between the outgoing international R2 register and an
incoming R2 register in an international exchange
Q.463 5.1.3 Signalling between the outgoing international R2 register and an
incoming R2 register in a national exchange in the destination country
Q.464 5.1.4 Signalling between the outgoing
international R2 register and the last incoming R2 register
Q.465 5.1.5 Particular cases
Q.466 5.1.6 Supervision and release of the call
Q.468
5.2 Rounting and numbering for international
working
5.3 Termination of
interregister signalling
Q.470 5.3.1 At an incoming R2 register
situated in a transit exchange
Q.471 5.3.2 At the last incoming R2 register
situated in the exchange to which the called subscriber is connected
Q.472 5.3.3 At the last incoming R2 register
situated in a transit exchange
Q.473 5.3.4 Use of end-of-pulsing signal I-15 in international working
Q.474 5.3.5 Use of group B signals
Q.475
5.4 Normal Release of outgoing and
incoming R2 registers
Q.476 5.5 Abnormal release of outgoing and
incoming R2 registers
Q.478 5.6 Relay and regeneration of R2
interregister signals by an outgoing R2 register in a transit exchange
Q.479
5.7 Echo-suppressor control –
signalling requirements
Q.480 5.8 Miscellaneous procedures
SECTION 6 – Testing and maintenance
Q.490 Testing
and maintenance
Annex A to Signalling System R2
Specifications – Provision of a forward-transfer signalling facility