1 Introduction
1.1 Scope
1.2 Outline of operational principles
1.3 Functions of the TPIWF
1.4 Special provisions for the use of PAD service signals within
the international telex service
2
Methods of interworking and addressable terminals
2.1 Considering
3
Access from the telex network to the PSPDN
3.1 One-stage selection
3.2 Two-stage selection
3.3 Data transfer phase – Packet forwarding conditions
4
Access from the PSPDN to the telex network
4.1 Call establishment
4.2 Text transfer phase
4.3 Reaction of TPIWF to data packets with M-bit set
4.4 Setting of PSPDN PAD parameters by TPIWF
5
WRU and answerback processing
5.1 Call established from the telex network to the PSPDN
5.2 Call established from PSPDN to the telex network
6
Clearing procedures
6.1 Clearing initiated within the PSPDN
6.2 Clearing initiated within the telex network
7
Ineffective call attempts
7.1 General
7.2 Ineffective calls within the telex network
7.3 Ineffective calls within the PSPDN
8
TPIWF PAD parameters
9
Abnormal conditions
9.1 Telex-to-PSPDN direction
9.2 PSPDN-to-telex direction
9.3 Flow control of the teleprinter
9.4 Detection of signals on the backward path during forward
transmission – Counterwriting
Appendix I – Handling of clearing procedures by TPIWF
I.1 General
I.2 Clearing initiated by PSPDN
I.3 Clearing initiated from the telex network
Appendix II – Reaction by the TPIWF to ineffective call attempts within the
telex network
II.1 General
II.2 Ineffective calls within the telex network