ITU U.203:1993
ITU U.203:1993 Technical Requirements To Be Met When Providing Real-time Bothway Communications Between Terminals Of The International Telex Service And Data Terminal Equipments On A Pspdn Or Via The Pstn
Table of Contents
1Introduction1.1Scope
1.2Outlineofoperationalprinciples
1.3FunctionsoftheTPIWF
1.4SpecialprovisionsfortheuseofPADservice
signalswithintheinternationaltelexservice
2Methodsofinterworkingandaddressableterminals
2.1Considering
3AccessfromthetelexnetworktothePSPDN
3.1One-stageselection
3.2Two-stageselection
3.3Datatransferphase-Packetforwardingconditions
4AccessfromthePSPDNtothetelexnetwork
4.1Callestablishment
4.2Texttransferphase
4.3ReactionofTPIWFtodatapacketswithM-bitset
4.4SettingofPSPDNPADparametersbyTPIWF
5WRUandanswerbackprocessing
5.1CallestablishedfromthetelexnetworktothePSPDN
5.2CallestablishedfromPSPDNtothetelexnetwork
6Clearingprocedures
6.1ClearinginitiatedwithinthePSPDN
6.2Clearinginitiatedwithinthetelexnetwork
7Ineffectivecallattempts
7.1General
7.2Ineffectivecallswithinthetelexnetwork
7.3IneffectivecallswithinthePSPDN
8TPIWFPADparameters
9Abnormalconditions
9.1Telex-to-PSPDNdirection
9.2PSPDN-to-telexdirection
9.3Flowcontroloftheteleprinter
9.4Detectionofsignalsonthebackwardpathduring
forwardtransmission-Counterwriting
AppendixI-HandlingofclearingproceduresbyTPIWF
I.1General
I.2ClearinginitiatedbyPSPDN
I.3Clearinginitiatedfromthetelexnetwork
AppendixII-ReactionbytheTPIWFtoineffectivecall
attemptswithinthetelexnetwork
II.1General
II.2Ineffectivecallswithinthetelexnetwork