delim @@
| 5i'
|
SECTION 13 DEFINITIONS |
DEFINITIONS OF ESSENTIAL TECHNICAL TERMS
RELATING TO TELEGRAPH SWITCHING AND SIGNALLING
The definitions given below have been identified as necessary for studies in the field of telegraph switching and signalling.
Sub-numbers in the 721.XX.YY range signify correspondence with definitions in the International Electrotechnical Vocabulary (IEV) of the International Electrotechnical Commission (IEC).
Sub-numbers in the range 35.ZZ or 37.ZZ signify definitions derived from the ITU List of Definitions of Essential Telecommunications Terms.
F: reseau´ tel´ egraphique´ public
S: red telegrafica´ publica´
A telecommunication network set up to perform a telegraph service for the public.
Note -- A public telegraph network is supplied, operated and controlled by an Administration or recognized private operating agency.
F: reseau´ Gentex
S: red gentex´
Switched telegraph network used between Administrations or recognized private operating agencies to provide an international public telegram service.
Fascicle VII.2 -- U.140 1
F: ligne d'abonne;´ ligne de rattachement
S: linea´ de abonado; bucle de abonado
A link between equipment in a subscriber's premises and the local telecommunication centre providing required services.
721.51.03 .bp
F: liaison specialis´ ee´ (en tel´ egraphie´ et transmission de donnees)´
S: circuito especializado (circuito dedicado) (en telegrafia´ y transmision´ de datos
A telegraph link established permanently without the use of switching facilities and dedicated to the exclusive use of a set of terminals.
F: circuit international
S: circuito internacional
A circuit directly connecting two exchanges situated in different countries.
F: circuit intercontinental
S: circuito intercontinental
A circuit connecting two exchanges situated in different countries on different continents.
F: faisceau de circuits
S: haz (grupo) de circuitos
A group of circuits established between two exchanges, any circuit of which may be chosen without preference for the setting up of a connection.
2 Fascicle VII.2 -- U.140
F: reseau´ prive´ (en tel´ egraphie)´
S: red privada (en telegrafia)´
A group of terminals that can establish calls between one another without passing through the switching equipment of the public network.
F: poste principal d'un reseau´ prive´
S: posicion´ de desbordamiento (en una red privada)
A nominated terminal of a private network to which an incoming call is redirected if the terminal identification has been omitted or if connection to the selected terminal is not possible.
F: reseau´ prive´ ferme´
S: red privada cerrada
A private network that does not permit intercommunication other than between terminals connected to it.
721.51.11 .bp
F: interconnexion de reseaux´
S: interfuncionamiento de redes
The means whereby terminals connected to a telecommunication network may communicate with terminals of another network.
F: chemin
S: trajecto
In a telegraph network, a route between any two exchanges.
Fascicle VII.2 -- U.140 3
S: puerto (acceso)
A functional unit of an exchange through which signals can enter or leave a network.
F: liaison commutee´
S: conexion´ conmutada de circuitos
A temporary connection that is established on request between two or more stations in order to allow the exclusive use of that connection until it is released.
F: liaison multipoint
S: conexion´ multipunto
A connection established between three or more stations.
S: conexion´ punto a punto
A connection established between only two stations.
721.51.26 .bp
F: cha| ne de connexion
S: conexion´
A temporary association of channels or circuits, switching and other functional units set up to provide for the transfer of information between two or more points in a telecommunication network.
4 Fascicle VII.2 -- U.140
S: conexion´ (completa)
A temporary association of channels or circuits, switching and other functional units set up to provide for the transfer of information between terminals in a telecommunication network.
F: communication (telex)´
S: llamada (telex);´ comunicacion´ (telex)´
The establishment and possible use of a complete connection by connected telex terminals.
F: commutateur de rattachement
S: central de servicio de abonados
A public switching exchange which connects subscribers in a same area to one another, or which establishes connection between them and the other exchanges.
F: commutateur nodal tel´ egraphique´
S: centro de transito´
A telegraph exchange which enables connections between other telegraph exchanges to be established.
721.52.05 .bp
F: centre de commutation tel´ egraphique´
S: centro de conmutacion´ telegrafica´
The set of equipments installed at a single location to switch telegraph traffic.
Fascicle VII.2 -- U.140 5
F: sous-centre
S: subcentro
A switching centre which serves a group of terminals and concentrates the traffic from this group towards a larger parent switching centre in which it is dependent for the routing of the whole of its traffic.
F: concentrateur de lignes
S: concentrador de lineas´
A switching equipment remotely located in a local line network and enabling the traffic between the subscriber serving exchange and a number of subscribers to be carried by a smaller number of lines.
Note -- A compatible equipment must normally be provided at the subscriber serving exchange.
F: circuit interurbain
S: circuito interurbano
Telegraph circuit between two telegraph exchanges not belonging to the same local network.
F: jonction de sous-centre
S: circuito telegrafico´ de enlace
A telegraph circuit connecting a sub-centre with its parent switching centre.
F: groupement de lignes
S: servicio de lineas´ agrupadas
Several subscriber line circuits grouped under the same address in such a way that a call to that address may reach any of the free lines of the group.
721.52.12 .bp
6 Fascicle VII.2 -- U.140
|
28 |
overflow (in telegraphy) F: debordement´ (en tel´ egraphie)´ S: desbordamiento (en telegrafia)´ Redirection by the network of calls or messages to a designated position, when a connection to the called position |
cannot be established, with a view to a later retransmission.
F: commutation de circuits
S: conmutacion´ de circuitos
The temporary connection of two or more terminals upon request providing the exclusive use of a complete connection until it is released.
F: commutation de messages; messagerie
S: conmutacion´ de mensajes; conmutacion´ en el servicio de almacenamiento y retransmision´
The process of routing messages comprising, in certain nodes of the network, a receiving, storing as necessary, and forwarding of messages within a telecommunication network.
F: commutation avec retransmission par bande perforee´
S: conmutacion´ con retransmision´ por cinta perforada
A tape relay system in which the tape from a reperforator feeds directly into a permanently associated automatic transmitter which can be switched to an outgoing channel.
Note -- This switching may be manual, automatic or semi-automatic.
721.52.17
S: conmutacion´ de caracteres
The temporary connection of two or more terminals upon request using a process of storing and transferring character by character from one line to another.
Fascicle VII.2 -- U.140 7
|
33 |
circuit switching exchange; switch (circuit) F: commutateur de circuits S: centro de conmutacion´ de circuitos; conmutador (de circuitos) A set of devices associated with a set of circuits intended to interconnect temporarily on request such circuits to |
constitute connections.
721.52.19 .bp
|
34 |
message switching exchange; switch (message) F: commutateur de messages S: centro de conmutacion´ de mensajes; conmutador (de mensajes) A set of devices associated with a set of circuits intended to receive, store as necessary, and forward messages |
without providing any exclusive connection between circuits.
F: numero´ telex´ national d'abonne´
S: numero´ telex´ nacional de abonado
A sequence of digits that a caller must normally select to connect to a called subscriber situated in the same country.
F: numero´ telex´ local
S: numero´ de telex´ local
A sequence of digits shorter than the national subscriber's telex number used to connect a called subscriber situated in a restricted geographical area.
F: pluralite´ des codes de signaux de selection´
S: pluralidad de sen~ ales de seleccion´
8 Fascicle VII.2 -- U.140
The acceptance by the network of several different codes for selection signals, e.g. International Telegraph Alphabet No. 2 and International Alphabet No. 5, the choice of code being either fixed for a given subscriber, or variable at the subscriber's choice, for each call attempt.
S: prefijo de acceso a la red telex´ de larga distancia
A digit or sequence of digits giving access to the remainder of the national telex network from an area inside which local telex numbers are used.
S: prefijo de acceso a la red telex´ internacional
A digit or a sequence of digits that must be selected by a subscriber, possibly after the prefix giving access to the long distance telex network, to connect with the international network.
S: prefijo de acceso a la red telex´ intercontinental
A digit or a sequence of digits that must be selected by a subscriber, possibly after the prefix giving access to the long distance telex network, to connect with the intercontinental network.
721.52.31 .bp
F: code telex´ de destination
S: codigo´ de destino
A sequence of digits identifying the country in which the called subscriber is located or a specified network in that country.
Note -- The telex destination codes have been fixed by Recommendation F.69.
Fascicle VII.2 -- U.140 9
F: numero´ de batterie
S: secuencia de seleccion´ internacional
First sequence of digits in an international two-stage selection.
F: numerotation´ internationale en deux temps
S: seleccion´ internacional de dos etapas
The process of establishing international calls using two sequences of digits, the first sequence characterizing the called country or network, and the second sequence characterizing the called subscriber in that country or network.
|
44 |
traffic routing (in circuit switching) F: acheminement (en commutation de circuits) S: encaminamiento de trafico´ (en conmutacion´ de circuitos) Designating in accordance with given rules the set of circuits to be used for setting up a connection from a given |
exchange for a given call attempt.
|
45 |
normal (traffic) routing F: acheminement normal S: encaminamiento normal (de trafico)´ Designating in accordance with given rules the set of circuits on a first priority basis from which a circuit is to be |
selected, provided that a free circuit exists in that set for a given call attempt.
F: acheminement detourn´ e;´ detournement´
S: encaminamiento alternativo (de trafico)´
Designating in accordance with given rules the set of circuits to be taken in the case where no circuit is available in the set of normal traffic routing circuits for a given call attempt.
10 Fascicle VII.2 -- U.140
F: faisceau de premier choix
S: haz de circuitos de primera eleccion´
A set of circuits to be used on a first priority basis if a free circuit from this set is available.
721.52.39 .bp
F: acheminement de secours
S: encaminamiento de emergencia
The routing to be chosen exceptionally if neither the normal traffic routing nor any alternative traffic routing set of circuits is available.
F: reacheminement´
S: reencaminamiento
In case of congestion in a transit exchange, the re-direction of the call backwards to a preceding exchange in the already partly established connection with a view to finding an alternative traffic routing from that exchange.
F: signal de commutation
S: sen~ al de conmutacion´
A signal transmitted between two exchanges or between one exchange and a terminal for establishing and clearing a call.
F: signal (de commutation) vers l'avant
S: sen~ al de conmutacion´ hacia adelante
A switching signal transmitted in the direction from the caller to the called party.
Fascicle VII.2 -- U.140 11
S: sen~ al de conmutacion´ hacia atras´
A switching signal transmitted in the direction from the called party to the caller.
F: etat´ de disponibilite´
S: estado de circuito libre
The characteristic state of a circuit available for the setting up of a call.
F: signal d'appel
S: sen~ al de llamada
A forward switching signal retransmitted on a circuit or a subscriber's line to indicate that the setting up of a call is requested.
35.15 .bp
F: procedure´ de commande d'appel
S: procedimiento de control de la llamada
The entire set of interactive signals necessary to establish, maintain and release a call.
F: signal de confirmation d'appel
S: sen~ al de confirmacion´ de llamada
A return switching signal, in response to a calling signal, to acknowledge the receipt of the calling signal.
12 Fascicle VII.2 -- U.140
F: signal d'acceptation d'appel
S: sen~ al de llamada aceptada; sen~ al de aceptacion´ de la llamada
A signal sent over the return channel, indicating that the call can be accepted by a terminal.
F: sequence´ de selection´
S: sen~ ales de seleccion´
A sequence of forward signals giving to an exchange information necessary to the setting up of a call.
|
59 |
address (in circuit switching) F: adresse (en commutation de circuits) S: direccion´ (en conmutacion´ de circuitos) The part of the selection signals which indicates the destination of a call. |
||
721.52.55
|
60 |
address (in information processing) F: adresse (en traitement de l'information) S: direccion´ (en tratamiento de la informacion)´ A character or group of characters that identifies a storage or a device without the use of any intermediate |
reference.
S: sen~ al de invitacion´ a marcar
A return switching signal transmitted by an exchange in response to a calling signal or after a call-confirmation signal to indicate that the exchange is ready to receive the selection signals.
35.17 .bp
62 (user) class of service signal
Fascicle VII.2 -- U.140 13
F: signal de categorie´
S: sen~ al de clase de servicio (de usuario)
A character or group of characters among the selection signals identifying the user's class of service of the calling party.
F: presignal´
S: presen~ al
A class of service signal transmitted at the beginning of the selection signals.
F: postsignal
S: postsen~ al
A class of service signal transmitted after the sequence of digits characterizing the called terminal.
F: signal de fin de selection´
S: sen~ al de fin de seleccion´
A switching signal transmitted among the selection signals after the digits of the called subscriber's number to indicate that there is no further digit belonging to this number.
F: numerotation´ au clavier (en tel´ egraphie)´
S: seleccion´ por teclado (marcacion´ por teclado)
In automatic telegraph switching, the use of telegraph alphabet signals sent from the teleprinter's keyboard or from an automatic equipment to form the selection sequence.
67 dial selection (in telegraph)
F: numerotation´ au cadran (en tel´ egraphie)´
14 Fascicle VII.2 -- U.140
S: seleccion´ por disco (marcacion´ por disco) (en telegrafia)´
In automatic telegraph switching, the use of dial pulse trains from a dial or an automatic equipment to form the selection sequence.
F: signal de communication etablie´
S: sen~ al de comunicacion´ establecida
The switching signal returned over the backward signalling path to indicate that the call is extended to the called station.
35.19 .bp
F: signal de liberation´
S: sen~ al de liberacion´
The switching signal transmitted over a circuit to release a switched connection.
F: signal de confirmation de liberation´
S: sen~ al de confirmacion´ de liberacion´
Return switching signal which indicates that the clearing signal has been executed.
F: signal de service
S: sen~ al de servicio
Signal transmitted automatically by the network to the calling terminal indicating the progress of a call or the cause of failure of the call attempt.
Fascicle VII.2 -- U.140 15
F: signal d'occupation
S: sen~ al de ocupado; sen~ al de ocupacion´
A busy signal which indicates that the called station is busy or not available.
F: signal d'interdiction
S: sen~ al de acceso prohibido
A service signal which indicates that a call cannot be established because access is barred.
F: temps d'etablissement´ d'une communication
S: tiempo de establecimiento de la comunicacion´
The interval of time between the sending of the calling signal by the calling party and the reception of the call-connect signal.
F: temps de pres´ election´
S: tiempo de preseleccion´
The interval of time between the sending of the calling signal by the calling party and the reception of the proceed-to-select signal.
721.52.71 .bp
F: temps de numerotation´
S: tiempo de seleccion´ (tiempo de marcacion)´
The interval of time between the reception by the calling party of the proceed-to-select signal and the end of reception by the exchange of the selection sequence.
16 Fascicle VII.2 -- U.140
F: temps de selection´
S: periodo de espera despues´ de marcar
The interval of time between the end of the sending of the selection sequence by the calling party and the reception of the call-connect signal.
F: duree´ d'une communication
S: duracion´ efectiva de una comunicacion´
The interval of time between the reception by the calling party of the call-connect signal and the sending of the clearing signal.
F: commande par programme enregistre´
S: control por programa almacenado (CPA)
The control of an exchange by means of a set of instructions which are stored and can be modified.
F: signalisation par canal semaphore;´ signalisation sur voie commune
S: sen~ alizacion´ por canal comun´
A signalling method in which signalling information relating to a multiplicity of circuits is conveyed over a single channel by labelled messages.
F: signalisation voie par voie
S: sen~ alizacion´ asociada al canal
A signalling method in which the signals for the traffic carried by a single transmission channel are transmitted over that channel itself or over a signalling channel permanently associated with it.
Note -- This term may also apply when the signals for a circuit are transmitted over the channel carrying the traffic.
Fascicle VII.2 -- U.140 17
F: temps de liberation´
S: tiempo de liberacion´ de la llamada
The interval of time between the beginning of the sending of the clearing signal by a terminal and the appearance of the free circuit condition on the return line.
721.52.78 .bp
F: appel infructueux
S: llamada infructuosa
A call attempt which does not result in the establishment of a complete connection.
F: signal de refus d'appel
S: sen~ al de rechazo de la llamada
A call control signal sent by the called terminal to indicate that it does not accept the incoming call.
F: appel perdu
S: llamada perdida
A request for a connection which is rejected due to network congestion.
F: double prise (sur circuit mixte); collision frontale
S: colision´ frontal
The condition which exists when, on a transmission path capable of being used to set up calls in both directions, the path is seized from both ends simultaneously or nearly so. The seizure of the path by the distant end is not apparent, due to propagation delays.
18 Fascicle VII.2 -- U.140
|
87 |
terminal connection method (in telex) F: mode de raccordement (en telex)´ S: metodo´ de conexion´ del terminal (en telex)´ The characteristics of the interface between a telex subscriber's line and a subscriber-serving exchange. |
||
721.52.83
F: concentrateur-diffuseur
S: concentrador convertidor de velocidad
The temporary storing of data arriving from slow channels and their retransmission on high speed channels and vice versa.
F: centre directeur
S: estacion´ de control del sistema
Station which is responsible for maintenance and clearance of faults on a transmission system.
721.52.86 .bp
F: indication de duree´
S: indicacion´ de duracion´
The indication by the network to the paying terminal of the chargeable time of a call prior to the release of the paying terminal or by recall at a convenient time.
Note -- This information may be provided automatically or on demand.
INTERWORKING BETWEEN THE TELETEX SERVICE
AND THE TELEX SERVICE
(Melbourne, 1988)
Fascicle VII.2 -- Rec. U.201 19
1.1 This Recommendation defines the procedures to be followed for interworking between the Teletex service and the telex service.
1.2 This Recommendation is one of the a series which define interworking between the telex service and the Teletex service.
|
The other Recommendations are: a) Recommendation F.200: |
Teletex service |
|
|
b) Recommendation T.390: c) Recommendation F.201: |
Requirements for interworking with the telex service Interworking between the Teletex service and the telex service -- General |
|
2.1 |
Types of interworking 2.1.1 Interworking between the Teletex service and the telex service consists of two directions: a) the telex to Teletex direction; b) the Teletex to telex direction. |
|
|
2.2 2.2.1 |
Methods of interworking considering : (a) that the Teletex service can be provided upon various networks (see Recommendation F.200, § 2); (b) that an Administration can provide the Teletex service on more than one network (e.g. PSTN and PSPDN | | |
|
|
| ); |
||
|
(c) that the technical constraints of the existing networks (e.g. numbering plans, | | | ), the two following methods of interworking between the telex service and the Teletex service can be provided: i) interworking with one-stage selection; |
ii) interworking with two-stage selection.
or a recognized private operating agency.
20 Fascicle VII.2 -- Rec. U.201
2.2.2 The service requirements of each method are described in Recommendation F.201, §§ 3 and 4 respectively.
|
3.1 |
One-stage selection Recommendation F.201, § 3 describes the service principles for this method of interworking. |
|
|
3.1.1 |
Access from a manual telex terminal Interworking in the telex to Teletex direction using one-stage selection, in case of manual terminals, is described |
in Figure 1/U.201 and associated notes.
Figure 1/U.201, p.
Fascicle VII.2 -- Rec. U.201 21
Figure 1/U.201 [1t1.201], p. 22 Fascicle VII.2 -- Rec. U.201
Figure 1/U.201 [2T1.201], p. Fascicle VII.2 -- Rec. U.201 23
3.1.2 Access from a telex automatic emitting device (TAED)
Interworking on the telex to Teletex direction, using one-stage selection, in case of TAEDs is described in Figure 2/U.201 and associated notes.
|
Figure 2/U.201, p. Figure 2/U.201 [T2.201], p. |
24 Fascicle VII.2 -- Rec. U.201
|
3.2 3.2.1 |
Two-stage selection Service principles Recommendation F.201, § 4, describes the service principles for this method of interworking. |
|
|
3.2.2 |
Access from a manual terminal 3.2.2.1 Interworking in the telex to Teletex direction, using two-stage selection, in case of manual terminals, is |
described in Figure 3/U.201 and associated notes.
Figure 3/U.201, p.
Fascicle VII.2 -- Rec. U.201 25
Figure 3/U.201 [T3.201], p. 26 Fascicle VII.2 -- Rec. U.201
3.2.2.2 Address input
3.2.2.2.1 Single address input format
a) Case 1 -- If the telex subscriber has a processable answerback according to Recommendation U.74, minimum address input is:
|
Teletex address is the call-numeric string necessary to select the Teletex terminal, i.e. |
Table, p. |
-- if there is only one network supporting the Teletex service, the Teletex address is the national Teletex number;
-- if there is more than one network supporting the Teletex service, the Teletex address includes the DNIC/TCC number according to Recommendation X.121. DNIC or TCC may be separated from the national Teletex number by a hyphen (-), Combination No. 1 of ITA2.
b) Case 2 -- If the telex subscriber has a non-processable answerback according to Recommendation U.74, he should input the following string:
Table, p. Telex address is the Recommendation F.69 code followed by the national telex number. Any spaces shall be ignored by the CF.
c) Case 3 -- A telex subscriber may omit specifying the calling address, either inadvertently or intentionally, by transmitting:
|
In this case no ``ADD'' signal should be sent by the CF. |
Table, p. |
d) Remark -- In all cases the signal ``+'' is not to be used within the address input for other purposes than to indicate ``end of address''.
3.2.2.2.2 Multiple address input facility
-- This facility enables the calling telex subscriber to deposit messages addressed to multiple Teletex recipients.
-- If this facility is provided by the CF, the calling telex subscriber should separate each Teletex address (including or not the mnemonic part) by:
[T4.201], p.
Fascicle VII.2 -- Rec. U.201 27
-- The input of the last address, the calling telex address (if required) and the EOA signal, shall follow the rules established for the single address in § 3.2.2.2.1 of this Recommendation.
-- The calling telex subscriber should know whether the called CF offers the multi-address facility. However, if the facility is invoked by the calling telex subscriber but not offered by the CF, this will be treated as an abnormal condition and the suggested reaction of the CF is in the annex to this Recommendation.
28 Fascicle VII.2 -- Rec. U.201
3.2.2.3 Request for positive delivery notification (PDN)
-- If this facility is provided by the CF the method of requesting a PDN shall be to follow the Teletex address (or each Teletex addresses if multi-address is also offered) for which a PDN is required, by the sequence:
H.T. [T5.201]
|
center box; cw(48p) | cw(48p) . , |
ACK _ |
|||
|
Table [T5.201], p. |
||||
|
-- Example: (in this example both . | | 3029 - 500 9145 = XYZ, ACK 3029 - 500 9090 + . | | |
the PDN and the multi-address facilities are offered) |
-- The possibility of requesting a PDN for all Teletex addresses by means of a single indicator, is for further study.
-- The calling telex subscriber should be aware whether the CF offers this facility or not.
However, if a calling telex subscriber requests a PDN from a CF which does not offer this facility, this shall be treated as an abnormal condition and is described in the annex to this Recommendation.
3.2.2.4 Validation result
|
3.2.2.4.1 Positive validation result -- The format of the positive validation result is: H.T. |
[T6.201] |
|
center box; cw(48p) | cw(30p) | cw(30p) | cw(30p) | cw(90p) . ¬ º |
¯ VAL ñ Telex terminal identification _ Table [T6.201], p. |
-- The Teletex terminal identification shall be in accordance with Note 6 to Figure 7/U.201.
-- The format of the progress signal following the validation result is:
H.T. [T7.201]
|
center box; cw(60p) | cw(48p) . ¬ º ¯ |
GA _ |
Table [T7.201], p. |
-- If the CF offers the multi-address input facility, validation of addresses shall continue until a valid address is found.
-- If the timing constraints have been met (i.e. a valid address has been found within 5 seconds of receipt of the EOA signal) it is the Teletex terminal identification of this valid address which is returned with the validation result, in the format described above.
-- Where time to find a valid address exceeds 5 seconds after receipt of the EOA signal, the CF shall behave according to § 4.1.4 of Recommendation F.201 and Table 1/F.201.
3.2.2.4.2 Negative validation answer
Fascicle VII.2 -- Rec. U.201 29
-- If the validation leads to a negative result, the CF should send at least the telex service signal ``NP'' or, if available, other appropriate service signals according to Recommendation U.70. The CF should then clear the call.
-- Where the CF offers multi-address input, all addresses shall be validated. As this may be difficult in real-time, the CF should return the addresses found to be invalid in a single non-delivery notification.
30 Fascicle VII.2 -- Rec. U.201
4.2.2.4.3 Action of the CF following validation
The action of the CF following validation shall be as prescribed in § 4.1.4 of Recommendation F.201, and Table 1/F.201.
3.2.2.5 Input message acknowledgement
|
The input message acknowledgement (IMA) is to be returned by the CF to the calling telex subscriber after the EOI. This information is used as the message reference in case of notifications (NDN or PDN). The format of the input message acknowledgement is: H.T. [T8.201] center box; cw(42p) | cw(36p) | cw(90p) | cw(60p) . ¬ º ¯ IMA { ñ yy ñ mm ñ dd ñ hh:mm ¬ º |
|
} |
xxx xxx ¬ º _ |
Table [T8.201], p. |
where the xxx xxx¬ º is an additional reference number and is optional.
3.2.2.6 Notifications format
3.2.2.6.1 Non-delivery notification (NDN) format
-- The NDN message has the format and content described in Figure 4/U.201:
H.T. [T9.201]
center box; lw(12p) | cw(126p) | cw(90p) . Field Comment _ lw(12p) | lw(126p) | lw(90p) . Telex subscriber's answerback _ cw(12p) | lw(126p) | lw(90p) . C o n t e n t { ¬ º CF NATIONAL NUMBER ñ ¯ T ñ TTX ñ s/ [¯] ¬ º ¬ º ¬ º NDN [ñ TELETEX] ¬ º YY ñ MM ñ DD ñ HH:MM ¬ º ¬ º ¯ TELETEX ñ ADDRESS :XX -- -- -- XX ¬ | (== | (da | MA | (ra | (ua | Y | (ra | M | (ra | D | (ra | H:MM | (<- | (== | xxxxxx | (<- º] ¬ º ¯ CAUSE :xxx | (<- º ¬ º ¬ º
} { Date and time of the CF Address received by the CF during deposit (The same information as given after the input of the message) Telex service signal of the last delivery attempt, as specified in Recommendation U.70
|
} _ cw(12p) | lw(126p) | lw(90p) . NUMBER ñ ¯ T ñ TTX ñ s/ } cw(12p) | lw(126p) | lw(90p) . |
Telex subscriber's answerback _ cw(12p) | lw(126p) | lw(90p) . { ¬ º ¬ º ¬ º ¬ º ¬ º ¬ º ¬ º ¬ º |
{ ¬ º CF NATIONAL |
||
|
.TE |
||||
|
Note -- Text given in [ | is optional. |
Figure shift ¬ Carriage return º Line feed ¯ Letter shift ñ Space
|
FIGURE 4/U.201 |
||
|
Table Fascicle VII.2 -- Rec. U.201 31 |
Table [T9.201], p. |
When the multi-address facility is offered, one separate NDN is returned to the originator, for each non-delivered address (recipient).
|
3.2.2.6.2 Positive delivery notification (PDN) format -- The PDN message has the format and content described in Figure 5/U.201. |
|
|
Figure 5/U.201 [T10.201], p. |
|
|
Blanc 32 Fascicle VII.2 -- Rec. U.201 |
3.2.2.7 Text delivery
3.2.2.7.1 Text delivery with ODA
If the CF provides the On-line delivery acknowledgement (ODA) facility, it sends a MOM signal immediately after the IMA.
The CF attempts to establish the delivery call within a maximum pariod of 30 seconds, with several attempts (at least one in the case of PSTN). Attempts should be made at 5-second intervals measured from the end of one attempt to the beginning of the next.
A MOM signal is returned after each attempt followed eventually by network service signals.
If the message delivery succeeds the CF returns to the telex user the called party's Teletex answerback, as described in Note 6 of Figure 7/U.201, and clears the call.
If the Teletex call establishment fails within 30 seconds, the CF sends service signal ``ITL'' and clears the call, the procedure is then as in § 3.2.2.7.2 below.
3.2.2.7.2 Text delivery without ODA
|
If the ODA facility is not provided, the CF sends a service signal ``ITL'' immediately after the IMA, and clears the call. After sending an ITL signal, in all cases, the CF should attempt to deliver the message within four hours. The CF should make at least 16 |
||
|
series |
of four calls, with 15 minutes between each series. (These figures may be revised in some cases, e.g. in the case of a PSTN.) If the delivery fails despite the performance of the cycle of delivery attempts, the CF should send a non-delivery notification (NDN) with the |
format described in § 3.2.2.6.1.
3.2.2.8 Follow-on message facility
-- Where this facility is offered, rather than clearing the call (as stated in §§ 3.2.7.1 and 3.2.7.2) the CF should generate a prompt in the format below:
H.T. [T11.201]
|
center box; cw(60p) | cw(60p) . ¬ º ¯ |
TTXñ NBR: _ |
Table [T11.201], p. |
-- The CF shall wait up to 15 seconds for the start of a new input to appear, after this delay the CF shall clear the call.
-- The CF shall treat the follow-on message as if it had been received in a completely separate session.
Blanc
Fascicle VII.2 -- Rec. U.201 33
3.2.3 Access from a telex automatic emitting device (TAED)
3.2.3.1 Interworking on the telex to Teletex direction, using two-stage selection, in case of TAEDs is described in Figure 6/U.201 and appending notes.
Figure 6/U.201, p. 34 Fascicle VII.2 -- Rec. U.201
Figure 6/U.201 [T12.201], p. 3.2.3.2 Address input
3.2.3.2.1 Single address input format
a) Case 1 -- Whether or not the telex subscriber has a processable answerback according to Recommendation U.74, he should input his telex address as described below:
Table, p.
-- The start of address ``CI'' informs the CF that prompts that validation information and WRU signal must not be returned to the telex automatic emitting devices.
Fascicle VII.2 -- Rec. U.201 35
-- Teletex address and telex address have the same definition as in § 3.2.2.2.1 to this Recommendation. 36 Fascicle VII.2 -- Rec. U.201
b) Case 2 -- A telex subscriber may omit his address input either inadvertently or intentionally by transmitting:
|
c) |
Remark |
Table, p. |
In all cases:
-- no ``ADD'' signal should be sent by the CF;
-- the signal ``+'' is not to be used within the address line for other purposes than to indicate ``end of address''.
3.2.3.2.2 Multi-address input format
(See § 3.2.2.2.2, Recommendation U.201.)
3.2.3.3 Positive delivery notification (PDN) facility request
(See § 3.2.2.3.)
3.2.3.4 Validation result
3.2.3.4.1 Positive validation answer
-- The result of the address validation, if positive, should be sent to the user together with the IMA, after successful completion of the message input.
-- The positive validation result, in the format defined in § 3.2.2.4.1 of Recommendation U.201, and the IMA in the format defined in § 3.2.2.5, should follow without pause, the transmission of the CF's answerback in response to the first ``WRU'' requested by the user after the end of message input ``EOI'' (see step referred by Note 10 in Figure 6/U.201).
-- If no answerback is requested by the telex user at this stage (Note 10, Figure 6/U.201) positive validation answer and IMA cannot be returned.
-- In all cases, if a second WRU is issued by the telex user, at this stage (Note 10, Figure 6/U.201), the CF shall return only its answerback.
-- This is in order to allow a positive match, if the telex TAED performs a comparison between the answerbacks returned at the start and the end of the call.
-- Where the multi-address input facility is offered the CF should continue validating addresses until a valid one is found, and return the result of the first positive one in the way described above.
3.2.3.4.2 Negative validation answer
If the validation result is negative, the CF should transmit sequences of characters ``T'' according to Recommendation S.4 to interrupt the telex terminal transmission. If the terminal continues to transmit for more than 20 seconds, the CF shall clear the call. This will be followed, after a pause of one second, by the appropriate service signal, according to Recommendation U.70, and clear the call.
Where the multi-address input facility is provided and all addresses are found to be invalid, this should be treated as a negative validation result and the CF shall act in accordance with § 4.1.4 of Recommendation F.201 and Table 1/F.201.
Fascicle VII.2 -- Rec. U.201 37
3.2.3.5 Notification formats
Positive and negative notification (PDN and NDNs) formats are as described in §§ 3.2.2.6.2 and 3.2.2.6.1 respectively. 38 Fascicle VII.2 -- Rec. U.201
|
4.1 |
Service principles Recommendation F.201, §§ 3.2 and 4.2 describe the service principles for this direction. |
|
|
4.2 |
Text delivery After clearing, the CF should attempt to deliver the message within four hours. The CF should make at least 16 series of four calls, with |
15 minutes between each series. (These figures may be revised in some cases, e.g. in the case of a PSTN.)
If the delivery fails despite the performance of the cycle of delivery attempts, the CF should send a non-delivery notification (NDN). This information is sent to the Teletex user with the complete reference of the related message in order to allow the Teletex user to take further action. No further delivery action shall be taken by the CF.
Text delivery to the telex terminal is described by Figure 7/U.201, for both one- and two-stage selection CFs.
|
The main difference between these two CFs is the content of the answerback of the CF. |
|||
|
Figure Fascicle VII.2 -- Rec. U.201 39 |
Figure 7/U.201, p. |
Figure 7/U.201 [1T13.201], p. 40 Fascicle VII.2 -- Rec. U.201
|
A.1 |
ANNEX A (to Recommendation U.201) Reactions to abnormal conditions during the telex input Telex connection clearing without the end of input signal |
Figure 7/U.201 [2T13.201], p. |
After a clear without the end of input (EOI) signal, the conversion facility should forward the message to the Teletex subscriber.
A.2 Telex subscriber pausing during input of address information
If there is a delay greater than 15 seconds at the start of the address input or between characters within the address input, the CF shall clear the connection.
A.3 Telex subscriber stopping transmission without sending the end of input signal
After at least a 30 seconds time-out, the conversion facility should send a prompt ``GA'' to the telex subscriber in order to request more information input (e.g. a text or the end of the input signal). If after a further 30 seconds time-out there is no more information, then the conversion facility should send the input message acknowledgement signal, followed by a service message BK. After this the conversion facility should clear the call.
A.4 Telex subscriber sending a WRU to the conversion facility during text input
i) In case of one-stage selection procedure, the CF should return the rearranged Teletex answerback (see Note 3 of Figure 1/U.201).
ii) In case of two-stage selection procedure, in any step of the procedure, the conversion facility should return its answerback after receiving a WRU. In addition:
-- if WRU is followed by text, message input is continued after the conversion facility answerback. Also the WRU is deleted from the message text;
-- if WRU is followed by a clear from the telex network, the conversion facility proceeds as in § A.1 above;
-- if WRU is followed by an idle condition, the conversion facility proceeds as in § 3 above.
A.5 Telex subscriber sending a text after the end of input signal
Any characters received after the end of input signal will be ignored. The conversion facility should use the ``TTT | | | '' characters to attempt to stop the telex transmission and if successful, then send an input message acknowledgement signal followed by clearing. After clearing, the message should be normally forwarded to the Teletex terminal.
This does not apply in a case of a two-stage selection CF offering the follow-on message facility.
A.6 Telex subscriber clearing after the end of input signal and before the input message acknowledgement signal
The message shall be normally forwarded to the Teletex terminal.
Fascicle VII.2 -- Rec. U.201 41
A.7 Telex subscriber sending national variants of ITA2 characters (figure shift characters of F, G and H)
These combinations could either be converted into a Teletex code which is a non-telex character (e.g. ``*''), or into the national use of these combinations. The choice is a national matter.
|
A.8 |
The conversion facility detecting signal distorsion during text input Reactions to the detection of distorsion are a national matter. |
||
|
A.9 |
Telex subscriber sending a bell signal The conversion facility has to ignore the bell signal in text input. |
||
|
A.10 |
CFs storage capacity overflow during telex message input -- In order to avoid memory overflow occurring during message input, a guaranteed |
a guaranteed message length of 12 | 00 characters is defined. |
|
|
-- The CF should return an ``NC'' service signal if guaranteed storage space -- Messages exceeding the guaranteed length will continue to be accepted -- If the number of characters received by the conversion facility during a message |
space is not available. if storage is available. a message input exceeds the available storage to that input, |
the conversion facility should discard the excess characters and no attempt should be made by the conversion facility to overwrite previously stored characters. When this occurs, the conversion facility should immediately attempt to prevent the telex subscriber from sending further characters by transmitting a sequence of ``TTT. | | '' characters for a maximum of 20 seconds.
If the calling terminal stops transmission within this period, the conversion facility should return the message length exceeded indication, ``LDE'', return IMA in case of the two-stage selection procedure and then behave as normal, as if the text input phase had finished.
If the terminal continues to transmit characters after this period, the conversion facility should forcefully clear the connection.
-- The conversion facility should attempt to deliver the message text, accepted and stored, preceded by a special text prefix to indicate to the called Teletex subscriber that the message may be incomplete.
A.11 Request of optional facilities, when not provided by the CF
If a user requests an optional facility not offered by a CF (e.g. multi-address or positive delivery notification), the CF shall use sequences of character ``T'' (according to Recommendation S.4) to attempt to stop the telex transmission. After the successful stop, the CF should then send an ``NA'' service signal.
42 Fascicle VII.2 -- Rec. U.201
Fascicle VII.2 -- Rec. U.201 43
44 Fascicle VII.2 -- Rec. U.201