Recommendation U.140 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. 1 public telegraph network F: r‚seau t‚l‚graphique public S: red telegr fica pblica 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. 721.51.01 2 Gentex network F: r‚seau Gentex S: red g‚ntex Switched telegraph network used between Administrations or recognized private operating agencies to provide an international public telegram service. 721.51.02 3 subscriber's line; subscriber loop F: ligne d'abonn‚; ligne de rattachement S: l¡nea 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 4 dedicated circuit (in telegraphy and data transmission) F: liaison sp‚cialis‚e (en t‚l‚graphie et transmission de donn‚es) S: circuito especializado (circuito dedicado) (en telegraf¡a y transmisi¢n de datos A telegraph link established permanently without the use of switching facilities and dedicated to the exclusive use of a set of terminals. 721.51.05 Fascicle VII.2 - Rec. U.140 PAGE1 5 international circuit F: circuit international S: circuito internacional A circuit directly connecting two exchanges situated in different countries. 721.51.06 6 intercontinental circuit F: circuit intercontinental S: circuito intercontinental A circuit connecting two exchanges situated in different countries on different continents. 721.51.07 7 set (group) of circuits 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. 721.51.08 8 private network (in telegraphy) F: r‚seau priv‚ (en t‚l‚graphie) S: red privada (en telegraf¡a) A group of terminals that can establish calls between one another without passing through the switching equipment of the public network. 721.51.09 9 overflow position (in a private network) F: poste principal d'un r‚seau priv‚ S: posici¢n 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. 721.51.10 10 closed private network F: r‚seau priv‚ ferm‚ S: red privada cerrada A private network that does not permit intercommunication other than between terminals connected to it. 721.51.11 PAGE1 Fascicle VII.2 - Rec. U.140 11 interworking between networks F: interconnexion de r‚seaux S: interfuncionamiento de redes The means whereby terminals connected to a telecommunication network may communicate with terminals of another network. 721.51.12 12 path F: chemin S: trajecto In a telegraph network, a route between any two exchanges. 721.51.21 13 (terminal) port F: accŠs S: puerto (acceso) A functional unit of an exchange through which signals can enter or leave a network. 721.51.22 14 circuit-switched connection F: liaison commut‚e S: conexi¢n 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. 721.51.24 15 multipoint connection F: liaison multipoint S: conexi¢n multipunto A connection established between three or more stations. 721.51.25 16 point-to-point connection F: liaison point … point S: conexi¢n punto a punto A connection established between only two stations. 721.51.26 Fascicle VII.2 - Rec. U.140 PAGE1 17 connection F: chaŒne de connexion S: conexi¢n 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. 721.52.01 37.18 18 (complete) connection F: chaŒne de connexion complŠte; (chemin de) communication S: conexi¢n (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. 721.52.02 19 (telex) call F: communication (t‚lex) S: llamada (t‚lex); comunicaci¢n (t‚lex) The establishment and possible use of a complete connection by connected telex terminals. 721.52.03 20 subscriber serving exchange 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. 721.52.04 21 transit exchange F: commutateur nodal t‚l‚graphique S: centro de tr nsito A telegraph exchange which enables connections between other telegraph exchanges to be established. 721.52.05 22 telegraph switching exchange F: centre de commutation t‚l‚graphique S: centro de conmutaci¢n telegr fica The set of equipments installed at a single location to switch telegraph traffic. 721.52.06 23 sub-centre F: sous-centre S: subcentro PAGE1 Fascicle VII.2 - Rec. U.140 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. 721.52.08 35.02 24 line concentrator F: concentrateur de lignes S: concentrador de l¡neas 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. 721.52.09 35.09 25 trunk circuit F: circuit interurbain S: circuito interurbano Telegraph circuit between two telegraph exchanges not belonging to the same local network. 26 telegraph junction circuit F: jonction de sous-centre S: circuito telegr fico de enlace A telegraph circuit connecting a sub-centre with its parent switching centre. 721.52.11 35.12(a) 27 overline service F: groupement de lignes S: servicio de l¡neas 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 28 overflow (in telegraphy) F: d‚bordement (en t‚l‚graphie) S: desbordamiento (en telegraf¡a) 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. 721.52.13 35.10 29 circuit switching F: commutation de circuits S: conmutaci¢n de circuitos The temporary connection of two or more terminals upon request providing the exclusive use of a complete connection until it is released. 721.52.14 30 message switching; store and forward switching F: commutation de messages; messagerie Fascicle VII.2 - Rec. U.140 PAGE1 S: conmutaci¢n de mensajes; conmutaci¢n en el servicio de almacenamiento y retransmisi¢n 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. 721.52.15 31 reperforator switching F: commutation avec retransmission par bande perfor‚e S: conmutaci¢n con retransmisi¢n 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 35.03 32 character switching F: commutation de caractŠres S: conmutaci¢n 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. 721.52.18 33 circuit switching exchange; switch (circuit) F: commutateur de circuits S: centro de conmutaci¢n 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 34 message switching exchange; switch (message) F: commutateur de messages S: centro de conmutaci¢n 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. 721.52.20 35 national subscriber's telex number F: num‚ro t‚lex national d'abonn‚ S: nmero t‚lex nacional de abonado A sequence of digits that a caller must normally select to connect to a called subscriber situated in the same country. 721.52.21 36 local telex number F: num‚ro t‚lex local S: nmero de t‚lex 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. 721.52.22 PAGE1 Fascicle VII.2 - Rec. U.140 37 alternative selection signals F: pluralit‚ des codes de signaux de s‚lection S: pluralidad de se¤ales de selecci¢n 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. 721.52.28 38 prefix giving access to the long distance telex network F: pr‚fixe d'accŠs … grande distance S: prefijo de acceso a la red t‚lex 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. 721.52.29 39 prefix giving access to the international telex network F: pr‚fixe d'accŠs … l'international S: prefijo de acceso a la red t‚lex 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. 721.52.30 40 prefix giving access to the intercontinental telex network F: pr‚fixe d'accŠs … l'intercontinental S: prefijo de acceso a la red t‚lex 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 Fascicle VII.2 - Rec. U.140 PAGE1 41 destination code F: code t‚lex de destination S: c¢digo 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. 721.52.32 42 international selection sequence F: num‚ro de batterie S: secuencia de selecci¢n internacional First sequence of digits in an international two-stage selection. 721.52.33 43 international two-stage selection F: num‚rotation internationale en deux temps S: selecci¢n 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. 721.52.34 44 traffic routing (in circuit switching) F: acheminement (en commutation de circuits) S: encaminamiento de tr fico (en conmutaci¢n 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. 721.52.36 45 normal (traffic) routing F: acheminement normal S: encaminamiento normal (de tr fico) 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. 721.52.37 46 alternative traffic routing F: acheminement d‚tourn‚; d‚tournement S: encaminamiento alternativo (de tr fico) 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. 721.52.38 47 first choice set of circuits F: faisceau de premier choix S: haz de circuitos de primera elecci¢n PAGE1 Fascicle VII.2 - Rec. U.140 A set of circuits to be used on a first priority basis if a free circuit from this set is available. 721.52.39 48 emergency routing 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. 721.52.40 49 re-routing F: r‚acheminement 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. 721.52.41 50 switching signal F: signal de commutation S: se¤al de conmutaci¢n A signal transmitted between two exchanges or between one exchange and a terminal for establishing and clearing a call. 721.52.42 51 forward switching signal F: signal (de commutation) vers l'avant S: se¤al de conmutaci¢n hacia adelante A switching signal transmitted in the direction from the caller to the called party. 721.52.43 52 return switching signal F: signal (de commutation) vers l'arriŠre S: se¤al de conmutaci¢n hacia atr s A switching signal transmitted in the direction from the called party to the caller. 721.52.44 Fascicle VII.2 - Rec. U.140 PAGE1 53 free circuit condition F: ‚tat de disponibilit‚ S: estado de circuito libre The characteristic state of a circuit available for the setting up of a call. 721.52.45 35.13 54 calling signal F: signal d'appel S: se¤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. 721.52.50 35.15 55 call control procedure F: proc‚dure 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. 721.52.51 56 call-confirmation signal F: signal de confirmation d'appel S: se¤al de confirmaci¢n de llamada A return switching signal, in response to a calling signal, to acknowledge the receipt of the calling signal. 721.52.52 35.16 57 call accepted signal F: signal d'acceptation d'appel S: se¤al de llamada aceptada; se¤al de aceptaci¢n de la llamada A signal sent over the return channel, indicating that the call can be accepted by a terminal. 721.52.53 58 selection signals F: s‚quence de s‚lection S: se¤ales de selecci¢n A sequence of forward signals giving to an exchange information necessary to the setting up of a call. 721.52.54 59 address (in circuit switching) F: adresse (en commutation de circuits) S: direcci¢n (en conmutaci¢n de circuitos) PAGE1 Fascicle VII.2 - Rec. U.140 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: direcci¢n (en tratamiento de la informaci¢n) A character or group of characters that identifies a storage or a device without the use of any intermediate reference. 721.52.56 61 processed-to-select signal F: signal d'invitation … num‚roter S: se¤al de invitaci¢n 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. 721.52.57 35.17 62 (user) class of service signal F: signal de cat‚gorie S: se¤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. 721.52.58 63 pre-signal F: pr‚signal S: prese¤al A class of service signal transmitted at the beginning of the selection signals. 721.52.59 64 post-signal F: postsignal S: postse¤al A class of service signal transmitted after the sequence of digits characterizing the called terminal. 721.52.60 Fascicle VII.2 - Rec. U.140 PAGE1 65 end of selection signal F: signal de fin de s‚lection S: se¤al de fin de selecci¢n 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. 721.52.61 66 keyboard selection F: num‚rotation au clavier (en t‚l‚graphie) S: selecci¢n por teclado (marcaci¢n 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. 721.52.62 67 dial selection (in telegraph) F: num‚rotation au cadran (en t‚l‚graphie) S: selecci¢n por disco (marcaci¢n por disco) (en telegraf¡a) In automatic telegraph switching, the use of dial pulse trains from a dial or an automatic equipment to form the selection sequence. 721.52.63 68 call-connected signal F: signal de communication ‚tablie S: se¤al de comunicaci¢n establecida The switching signal returned over the backward signalling path to indicate that the call is extended to the called station. 721.52.64 35.19 69 clearing signal F: signal de lib‚ration S: se¤al de liberaci¢n The switching signal transmitted over a circuit to release a switched connection. 721.52.65 35.20 70 confirmation of clearing signal F: signal de confirmation de lib‚ration S: se¤al de confirmaci¢n de liberaci¢n Return switching signal which indicates that the clearing signal has been executed. 721.52.66 71 service signal F: signal de service S: se¤al de servicio PAGE1 Fascicle VII.2 - Rec. U.140 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. 721.52.67 72 engaged; busy signal F: signal d'occupation S: se¤al de ocupado; se¤al de ocupaci¢n A busy signal which indicates that the called station is busy or not available. 721.52.68 73 barred signal F: signal d'interdiction S: se¤al de acceso prohibido A service signal which indicates that a call cannot be established because access is barred. 721.52.69 74 call set-up time F: temps d'‚tablissement d'une communication S: tiempo de establecimiento de la comunicaci¢n The interval of time between the sending of the calling signal by the calling party and the reception of the call-connect signal. 721.52.70 75 pre-selection delay F: temps de pr‚s‚lection S: tiempo de preselecci¢n 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 76 selection time F: temps de num‚rotation S: tiempo de selecci¢n (tiempo de marcaci¢n) 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. 721.52.72 Fascicle VII.2 - Rec. U.140 PAGE1 77 post-selection time F: temps de s‚lection S: periodo de espera despu‚s 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. 721.52.73 78 effective duration of a call F: dur‚e d'une communication S: duraci¢n efectiva de una comunicaci¢n The interval of time between the reception by the calling party of the call-connect signal and the sending of the clearing signal. 721.52.74 79 stored program control (SPC) F: commande par programme enregistr‚ 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. 721.52.75 80 common channel signalling F: signalisation par canal s‚maphore; signalisation sur voie commune S: se¤alizaci¢n por canal comn A signalling method in which signalling information relating to a multiplicity of circuits is conveyed over a single channel by labelled messages. 721.52.76 81 channel associated signalling F: signalisation voie par voie S: se¤alizaci¢n 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. 721.52.77 82 call clearing delay F: temps de lib‚ration S: tiempo de liberaci¢n 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 83 unsuccessful call F: appel infructueux S: llamada infructuosa PAGE1 Fascicle VII.2 - Rec. U.140 A call attempt which does not result in the establishment of a complete connection. 721.52.79 84 call not accepted signal F: signal de refus d'appel S: se¤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. 721.52.80 85 lost call F: appel perdu S: llamada perdida A request for a connection which is rejected due to network congestion. 721.52.81 86 head-on collision F: double prise (sur circuit mixte); collision frontale S: colisi¢n 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. 721.52.82 87 terminal connection method (in telex) F: mode de raccordement (en t‚lex) S: m‚todo de conexi¢n del terminal (en t‚lex) The characteristics of the interface between a telex subscriber's line and a subscriber-serving exchange. 721.52.83 88 speed converter concentrator 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. 721.52.84 Fascicle VII.2 - Rec. U.140 PAGE1 89 system control station F: centre directeur S: estaci¢n de control del sistema Station which is responsible for maintenance and clearance of faults on a transmission system. 721.52.86 90 indication of duration F: indication de dur‚e S: indicaci¢n de duraci¢n 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. 721.53.32 PAGE1 Fascicle VII.2 - Rec. U.140