5i' Recommendation M.60 MAINTENANCE TERMINOLOGY AND DEFINITIONS Introduction This Recommendation consists primarily of those terms and definitions that are considered essential to the understanding of the maintenance of services and networks. Reference is provided to relevant Recommendations from which these terms are derived. The terms and definitions are given with a section number. Annex A presents the list of terms in alphabetical order with the section number. For additional definitions concerning transmission systems, see Recommendation M.300; for additional definitions concerning maritime systems, see Recommendation M.1100; and for additional definitions concerning international sound-programme transmission, see Recommendation N.1, N.51 and N.81. Also, complementary defini- tions concerning transmission restoration can be found in Recommendation M.495. 1 alarm indication signal (AIS) F: signal d'indication d'alarme (SIA) S: se~al de indicacion de alarma (SIA) An alarm indication signal is a signal associated with a prompt maintenance alarm of a defective maintenance entity and is, when possible, transmitted in the direction affected (downstream direction) as a substitute for the normal signal, indicating to other non-effective entities that a failure has been identified and that other maintenace alarms consequent to this failure should be inhibited. (Rec. M.20) 2 anomaly F: anomalie S: anomalia An anomaly is a discrepancy between the actual and desired characteristic of an item. The desired characteristic may be expressed in the form of a specification. An anomaly may or may not affect the ability of an item to perform a required function. (Rec. M.20) 3 automatic switching equipment F: equipement de commutation automatique S: equipo de conmutacion automatica That part of an international exchange concerned with switch- ing operations for routing the call in the desired direction. (Rec. M.700, Red Book ) 4 availability (performance) F: disponibilite S: disponibilidad The availability of an item to be in the state to perform a required function at a given instant of time or at any instant of time within a given time interval, assuming that the external resources, if required, are provided. Note 1 - This ability depends on the combined aspects of the reliability performance, the maintainability performance and the maintenance support performance of an item. Note 2 - In the definition of the item the external resources required must be delineated. Note 3 - The term availability is used as an availability performance measure. (Supplement No 6, Fascicle II.3) 5 bit error ratio (BER) F: taux d'erreur sur les bits (TEB) S: tasa de errores en los bits; tasa de error en los bits (TEB) The ratio of the number of bit errors to the total number of bits transmitted in a given time interval. (Rec. E.800) 6 bridging loss F: affaiblissement d | a la derivation S: perdida por derivacion A term frequently used when a measuring instrument is con- nected (bridged) across a transmission path or telephone channel. The bridging loss is the resulting reduction in the signal level, and is usually expressed in dBs. 7 channel; access channel F: canal d'acces [canal] S: canal de acceso [canal] A designated part, having specified characteristics, of the information transfer capability at the user-network interface. Note 1 - The information transfer may be, and usually is, bi-directional. Note 2 - See also the definition for transmission channel. (Rec. I.112) 8 channel; transmission channel F: voie de transmission S: canal; canal de transmision See Recommendation M.300 for the definition of analogue chan- nel, digital channel and mixed analogue digital channel. 9 circuit; telecommunication circuit F: circuit; circuit de telecommunications S: circuito; circuito de telecomunicacion A combination of two transmission channels permitting bidirec- tional communication between two points, to support a single call. Note 1 - If the telecommunication is by nature unilateral, for example: long distance television transmission, the term "cir- cuit" is sometimes used to designate the single channel providing the facility. Note 2 - In telephony, use of the term "circuit" is generally limited to a telecommunication circuit with associated terminating equipment directly connecting two switching devices or exchanges. Note 3 - A telecommunication circuit does not necessarily permit simultaneous transmission in both directions. Note 4 - The "go" and "return" channels may be permanently associated together or may be selected from separate sets of asso- ciations together throughout the call. Note 5 - The term circuit may be preceded by other qualifiers than telecommunication e.g. telephone, digital, etc. (Rec. Q.9) 10 circuit; digital circuit F: circuit numerique S: circuito; circuito digital A circuit which transmits information signals in digital form between two exchanges. It includes termination equipment but not switching stages. (Rec. Q.9) 11 circuit access points F: points d'acces au circuit S: puntos de acceso al circuito Four-wire access points so located that as much as possible of the international circuit is included between corresponding pairs of these access points at the two centres concerned. These points, and their relative level (with reference to the transmission refer- ence point) are determined in each case by the Administration con- cerned. They are taken as the basic practical reference points of known relative level to which other transmission measurements will be related. In other words, for measurement and lining-up purposes, the level at the appropriate circuit access point is the relative level with respect to which other levels are adjusted. (Rec. M.565) 12 circuit control station F: station directrice de circuit S: estacion directora de circuito The circuit control station is the point within the general maintenance organization for the international automatic and semi-automatic telephone service that fulfils the control responsi- bilities for the automatic circuits assigned to it. (Rec. M.723) 13 circuit sub-control station F: station sous-directrice de circuit S: estacion subdirectora de circuito The circuit sub-control station is a point within the general maintenance organization for the international automatic and semi-automatic telephone service that assists the circuit control station and fulfils the control responsibilities for a circuit sec- tion assigned to it. (Rec. M.724) 14 code violation F: violation du code S: violacion de codigo Definition for code violation: a) AMI - Two consecutive marks of the same polar- ity. This may not be the absolute number of errors. b) HDB3 - Two consecutive bipolar violations of the same polarity. This may not be the absolute number of errors. c) B6ZS - Two consecutive marks of the same polar- ity excluding violations caused by the zero substitution code. This may not be the absolute number of errors. d) B8ZS - Two consecutive marks of the same polar- ity excluding violations caused by the zero substitution code. This may not be the absolute number of errors. (Rec. O.161) 15 connection F: cha | ne de connexion S: conexion An association of transmission channels or circuits, switching and other functional units set up to provide a means of transfer of information between two or more points in a telecommunication net- work. (Rec. Q.9) 16 connection; digital connection F: connexion numerique S: conexion digital A concatenation of digital transmission channels or digital telecommunication circuits, switching and other functional units set up to provide for the transfer of digital signals between two or more points in a telecommunication network, to support a single communication. (Rec. G.701) 17 connection; international connection F: communication internationale S: conexion internacional Whole of the means joining temporarily two subscribers and enabling them to exchange information. (Rec. M.700, Red Book ) 18 connection; international telephone connection F: communication telephonique internationale S: conexion telefonica internacional A complete international telephone connection has three parts, as shown in Figure 1/M.560: - an international chain - two national systems, one on each end. (Rec. M.560) 19 continuity check F: contr | le de continuite S: prueba de continuidad A check made to a circuit or circuits in a connection to ver- ify that an acceptable path (for transmission of data, speech, etc.) exists. (Rec. Q.9) 20 continuous checking F: contr | le continu S: comprobacion continua At the time an item is active, it is being checked for good performance. If the item does not fulfill the test requirements, it is considered to have failed. (Rec. M.20) 21 control station F: station directrice S: estacion directora A control station is that point within a general maintenance organization which fulfills the control responsibilities for the circuit, group, supergroup, digital section, etc., assigned to it. (Rec. M.80) 22 data communication network F: reseau de communication de donnees S: red de comunicacion de datos A data network which is established and operated either by Administrations or by private organizations. (Rec. X.15 Red Book ) 23 data communications network (DCN) F: reseau de communication de donnees (RCD) S: red de comunicacion de datos (RCD) A DCN is a communications network within the TMN which sup- ports the DCF at reference point q3. (Rec. M.30) 24 data communications function (DCF) block F: bloc de fonction de communication de donnees (FCD) S: bloque de funciones de comunicaciones de datos (FCD) The DCF block provides the means for data communication to transport information related to telecommunications management between function blocks. Details of the DCF are given in S 5.3 of Recommendation M.30. (Rec. M.30) 25 dead time F: temps mort S: tiempo muerto The dead time is defined for the purpose of Recommendations O.61 and O.62 as the time after which the counter is ready to record another interruption following the end of the preceding interruption. (Rec. O.61) 26 defect F: faute (ou defaut) S: defecto A defect is a limited interruption of the ability of an item to perform a required function. It may or may not lead to mainte- nance action depending on the results of additional analysis. (Rec. M.20) 27 deferred maintenance alarm (DMA) F: alarme de maintenance differee (AMD) S: alarma de mantenimiento diferido (AMD) A deferred maintenance alarm is generated when immediate action is not required by maintenance personnel, e.g. when perfor- mance falls below standard but the effect does not warrant removal from service, or generally if automatic changeover to standby equipment has been used to restore service. (Rec. M.20) 28 degraded minute (DM) F: minutes degradees (MD) S: minuto degradado (MD) A degraded minute is a group of 60 consecutive seconds, after excluding SES (severely errored seconds), with a BER (bit error ratio) of 10DlF2616 or worse. A pseudo-degraded minute is a group of 60 consecutive seconds, after excluding SES, with at least N2 anomalies or at least one slip (when the anomaly is not a binary error). N2 is calculated similarly to N1, to detect a BER of 10DlF2616 in one minute. (Rec. M.550) 29 echo F: echo S: eco An electric, acoustic or electromagnetic wave which arrives at a given point, after reflection or indirect propagation, with suf- ficient magnitude and delay for it to be perceptible at the given point, as a wave distinct from that directly transmitted. (Rec. G.601) 30 echo canceller F: annuleur d'echo S: compensador de eco; cancelador de eco A voice operated device placed in the 4-wire portion of a cir- cuit and used for reducing near-end echo present on the send path, by subtracting an estimation of that echo from the near-end echo. (Rec. G.165) 31 echo suppressor F: suppresseur d'echo S: supresor de eco A voice-operated device placed in the 4-wire portion of a cir- cuit and used for inserting loss in the transmission path to suppress echo. The path in which the device operates may be an individual circuit path or a path carrying a multiplexed signal. (Rec. G.164) 32 error F: erreur S: error An inconsistency between a digit in a transmitted digital sig- nal and the corresponding digit in the received digital signal. (Rec. G.701) 33 error; random error F: erreur aleatoire S: error aleatorio Errors distributed over the digital signal so that they can be considered statistically independent from each other. (Rec. Q.9) 34 error burst F: paquet d'erreurs S: rafaga de errores A group of bits in which two successive erroneous bits are always separated by less than a given number (x ) of correct bits. The number (x ) should be specified when describing an error burst. (Rec. Q.9) 35 error free seconds (EFS) F: secondes sans erreur (SSE) S: segundos sin error (SSE) The ratio of the number of one-second intervals during which no bits are received in error to the total number of one-second intervals in the time interval. Note 1 - The length of the time interval needs to be speci- fied. Note 2 - This ratio is usually expressed as a percentage. (Rec. E.800) 36 errored seconds F: secondes erronees (SE) S: segundos con error (SE) An errored second is a second with at least one anomaly or defect. (Rec. M.550) 37 exchange F: commutateur [central] S: central An aggregate of traffic carrying devices, switching stages, controlling and signalling means, and other functional units at a network node that enables subscriber lines, telecommunication cir- cuits and/or other functional units to be interconnected as required by individual users. (Rec. I.112) 38 failure F: defaillance S: fallo The termination of the ability of an item to perform a required function. Note - After failure the item has a fault. (Supplement No 6, Fascicle II.3; Rec. M.20) 39 fault F: panne; derangement S: averia The inability of an item to perform a required function, excluding that inability due to preventive maintenance, lack of external resources or planned actions. Note - A fault is often the result of a failure of the item itself, but may exist without prior failure. (Supplement No 6, Fascicle II.3; Rec. M.20) 40 fault; intermittent fault F: panne intermittente S: averia intermitente A fault of an item which persists for a limited time duration following which the item recovers the ability to perform a required function without being subjected to any action of corrective maintenance. Note - Such a fault is often recurrent. (Supplement No 6, Fascicle II.3) 41 fault correction F: correction (de panne) S: correccion (de una averia) Actions taken after a fault localization intended to restore the ability of the faulty item to perform a required function. (Supplement No 6, Fascicle II.3) 42 fault localization; localization of faults F: localisation des derangements S: localizacion (de una averia) The broad localization of fault consists in finding the gen- eral part of the equipment in which it exists. Fault finding con- sists of determining the faulty item of the equipment. (Rec. M.700, Red Book ) 43 fault report point (circuit) F: service de signalisation des derangements sur les cir- cuits S: punto de avisos de averias en los circuitos The fault report point (circuit) is an element within the gen- eral maintenance organization for the international automatic and semi-automatic telephone service at each international centre or common for more than one international centre. The fault report point (circuit) is equipped with all the necessary facilities and arranged in such a way that it may receive fault reports relating to one or more specifically identified cir- cuits from different sources or make such fault reports to other points and initiate the fault localization and clearing operations. The fault report point (circuit) will undertake its given responsibilities and functions for circuits provided by wholly analogue transmission and switching systems, and those provided by a mixture of analogue and digital systems. (Rec. M.715) 44 fault report point (network) F: service de signalisation des derangements dans le reseau S: punto de avisos de averias en la red The fault report point (network) is an element within the gen- eral maintenance organization for the international automatic and semi-automatic telephone service at each international centre or for more than one international centre. If more than one interna- tional centre is associated with a given relation, it is desirable to designate one fault report point (network) as the principle one for that relation. If such is not practical, one of the fault report points (network) or a central organization may be nominated to coordinate the activities of the various fault report points (network) that are involved. Such arrangements provide the maintenance organization of other Administrations with a single point of contact for directing fault reports and service problems which involve more than one international centre. While the fault report point (network) is essentially a maintenance element, it will in fact receive reports of network difficulties which may result in network management actions. In other cases, network fault reports may be explained by information already available to the network management (implementation and control point) and collected as a result of its network surveil- lance responsibility. Therefore, to avoid duplication of report points, considerable benefit is derived from close liaison between the fault report point (network) and the network management (imple- mentation and control point). (See Recommendation E.413.) The fault report point (network) is equipped with all the necessary facilities and arranged in such a way as to enable it: a) to receive from different sources, fault reports of difficulties on the international telephone network or of prob- lems with the international telephone service that, at the time of reporting, cannot be related to specific circuits or, in some cases, even to a specific international centre; and b) to make such fault reports to other points and initiate the fault location and clearing operations. (Rec. M.716) 45 interface F: interface S: interfaz The common boundary between two associated systems. (Rec. I.112) 46 international automatic circuit F: circuit automatique international S: circuito automatico internacional The whole of the international line and the outgoing and incoming equipment (or both-way equipments) proper to the automatic circuit considered. The ends of this circuit are defined by the circuit access points (see definition for circuit access points ). (Rec. M.700, Red Book ) 47 international chain F: cha | ne internationale S: cadena internacional An international chain is made up of one or more 4-wire inter- national circuits. These are connected on a 4-wire basis to inter- national circuits (in transit international centres) or to national systems (in terminal international centres). See Figure 1/M.560. (Rec. M.560) 48 international leased circuit F: circuit international loue S: circuit internacional arrendado The whole of the assembly of lines and apparatus connecting the renter's terminal equipment (e.g. data modem) in one country to the renter's terminal equipment in another. The interfaces between the circuit and the renter's terminal equipment will be defined by the respective Administrations. See Figure 2/M.1010. (Rec. M.1010) 49 international main section F: section internationale principale S: seccion principal internacional The whole of the assembly of national and international group or supergroup sections, between the defined test access points at the two terminal international centres (see Recommendation M.460). These access points should be the same points as those for the ends of the national main sections involved in the leased link. See Figure 1/M.900. (Rec. M.900) 50 interruption; break of service F: interruption; coupure (d'un service) S: interrupcion (de un servicio); corte (de un servicio) Temporary inability of a service to be provided persisting for more than a given time duration, characterized by a change beyond given limits in at least one parameter essential for service. Note 1 - An interruption of a service may be caused by dis- abled states of the items used for the service or by external rea- sons such as high service demands. Note 2 - An interruption of a service is generally an interruption of the transmission, which may be characterized by an abnormal value of power level, signal distortion, error rate, etc. (Rec. E.800) 51 interruption F: interruption S: interrupcion For the purpose of Recommendation O.61, an interruption shall be regarded as a break in transmission or drop in the level of a test tone below a designated threshold. (Rec. O.61) 52 interruption F: interruption S: interrupcion For the purpose of Recommendation O.62, an interruption shall be regarded as a break in transmission or drop in the level of a 2 kHz test tone below a designated threshold. (Rec. O.62) 53 line; international line F: ligne internationale S: linea internacional The transmission system contained between the line access points (see S 2 of Recommendation M.565) of the two terminal international centres. Where a digital international centre is interfaced by primary (or higher order) digital paths, a line access point on a per circuit basis may not exist. In such cases, the international line is deemed to end at the digital path access point nearest the international centre. (Rec. M.700, Red Book ) 54 line; international line F: ligne internationale S: linea internacional The whole of the assembly of international and national cir- cuit sections between terminal international centres. See Figure 2/M.1010. (Rec. M.1010) 55 line; national line F: ligne nationale S: linea nacional The whole of the assembly of national circuit sections con- necting the terminal national centre to the terminal international centre. When a distinction is needed to indicate the transmission direction in one country, the expressions national sending line, that is, outgoing from the render, and national receiving line, that is, incoming to the renter, may be used. See Figure 2/M.1010. (Rec. M.1010) 56 line access point F: points d'acces a la ligne S: puntos de acceso a la linea A point used by the CCITT to define the limits of an interna- tional line and from which measurements are made. Only one "line access point" exists at each end of an international line. The pre- cise location of each such point depends on the Administration con- cerned. (Rec. M.565) 57 link; international link F: liaison internationale S: enlace internacional The whole of the assembly of international and national cir- cuit sections between terminal national centres. See Figure 2/M.1010. (Rec. M.1010) 58 link; transmission link F: liaison de transmission S: enlace de transmision A means of transmission with specified characteristics between two points. Note - The type of the transmission path or the capacity is normally indicated, e.g. radio link, coaxial link, or 2048 kbit/s link. (Rec. I.112) 59 logistic delay F: delai logistique S: retardo logistico; demora logistica The logistic delay is the period of time between the fault localization and arrival of the maintenance staff on site. In case of an ISDN, the logistic delay will depend on the type of failures and how they are reported, i.e. by prompt maintenance alarm (PMA), deferred maintenance alarm (DMA) or maintenance event information (MEI). (Rec. M.20) 60 loopback F: mise en boucle S: bucle A mechanism incorporated into a terminal or into the network whereby the transmit path of a communication may be connected back upon the receive path. 61 loopback; complete loopback F: mise en boucle, complete S: bucle completo A complete loopback is a layer 1 [of the open system intercon- nection (OSI) model] mechanism which operates on the full bit stream. At the loopback point, the received bit stream shall be transmitted back towards the transmittting station without modifi- cation. (Rec. M.125) 62 loopback; digital loopback F: mise en boucle numerique S: bucle digital A digital loopback is a mechanism incorporated into a piece of equipment whereby a bidirectional communication path may be con- nected back upon itself so that some or all of the information con- tained in the bit stream sent on the transmit path is returned on the receive path. (Rec. M.125) 63 loopback; logical loopback F: mise en boucle logique S: bucle logico A logical loopback acts selectively on certain information within a specified channel or channels and may result in some specified modification of the looped information. Logical loopbacks may be defined at any layer of the OSI model depending on the detailed maintenance procedure specified. (Rec. M.125) 64 loopback; non-transparent loopback F: boucle non transparente S: bucle no transparente A non-transparent loopback is one in which the signal transmitted beyond the loopback point (the forward signal) when the loopback is activated is not the same as the received signal at the loopback point. The forward signal may be a defined signal or unspecified. (Rec. M.125) 65 loopback; partial loopback F: mise en boucle partielle S: bucle parcial A partial loopback is a layer 1 mechanism which operates on one or more specified channels multiplexed within the full bit stream. At the loopback point, the received bit stream associated with the specified channel(s) shall be transmitted back towards the transmitting station without modification. (Rec. M.125) 66 loopback; transparent loopback F: boucle transparente S: bucle transparente A transparent loopback is one in which the signal transmitted beyond the loopback point (the forward signal) when the loopback is activated, is the same as the received signal at the loopback point. (Rec. M.125) 67 loopback application F: application de la mise en boucle S: aplicacion de bucle The maintenance phase for which the loopback operation is used. (Rec. M.125) 68 loopback control mechanism F: mecanisme de commande de mise en boucle S: mecanismo de control de bucle The means by which the loopback is operated and released from the loopback control point. (Rec. M.125) 69 loopback control point F: point de commande de mise en boucle S: punto de control de bucle The loopback control point is the point which has the ability to directly control loopbacks. The loopback control point may receive requests for loopback operation from several loopback requesting points. (Rec. M.125) 70 loopback point F: point de mise en boucle S: punto de bucle A loopback point is the location of the loopback. (Rec. M.125) 71 loopback requesting point F: point de demande de mise en boucle S: punto de peticion de bucles The loopback requesting point is the point which requests the loopback control point to operate loopbacks. Note 1 - Loopback requests should be subject to identifica- tion and authorization. Note 1 - Possible locations of loopback requesting points are: in the network, in the TMN, in maintenance service providers (MSP). (Rec. M.125) 72 loopback test pattern F: signal destine a l'essai de mise en boucle S: secuencia de prueba de bucle The information transmitted during the operation of the loop- back in the channel or channels which are to be re-directed by the loopback. (Rec. M.125) 73 maintainability (performance) F: maintenabilite S: mantenibilidad The ability of an item under stated conditions of use, to be retained in, or restored to, a state in which it can perform a required function, when maintenance is performed under given condi- tions and using stated procedures and resources. Note - The term maintainability is used as a measure of main- tainability performance. (Supplement No 6, Fascicle II.3) 74 maintenance F: maintenance S: mantenimiento The whole of the operations required for setting up and main- taining, within prescribed limits, any element entering into the setting-up of a connection. In the international automatic tele- phone service, maintenance is particularly concerned with circuits and automatic switching equipment. Circuit and automatic equipment maintenance includes: a) carrying out setting-up measurements and adjust- ments; b) planning and programming a maintenance scheme; c) carrying out the prescribed routine preventive maintenance measurements and all other tests and measurements deemed necessary; d) locating and clearing faults. (Rec. M.700, Red Book ) 75 maintenance F: maintenance S: mantenimiento The combination of all technical and corresponding administra- tive actions, including supervision actions, intended to retain an item in, or restore it to, a state in which it can perform a required function. (Supplement No 6, Fascicle II.3) 76 maintenance; automatic maintenance F: maintenance automatique S: mantenimiento automatico Maintenance accomplished without human intervention. (Supplement No 6, Fascicle II.3) 77 maintenance; controlled maintenance F: maintenance dirigee S: mantenimiento dirigido A method to sustain a desired quality of service by the sys- tematic application of analysis techniques using centralized super- visory facilities and/or sampling to minimize preventive mainte- nance and to reduce corrective maintenance. (Rec. M.20) 78 maintenance; corrective maintenance F: maintenance corrective S: mantenimiento correctivo The maintenance carried out after fault recognition and intended to restore an item to a state in which it can perform a required function. (Rec. M.20) 79 maintenance; deferred maintenance F: maintenance differee S: mantenimiento diferido Such corrective maintenance which is not immediately initiated after a fault recognition, but is delayed in accordance with given maintenance rules. (Supplement No 6, Fascicle II.3) 80 maintenance; preventive maintenance F: maintenance preventive S: mantenimiento preventivo The maintenance carried out at predetermined intervals or according to prescribed criteria and intended to reduce the proba- bility of failure or the degradation of the functioning of an item. (Rec. M.20) 81 maintenance entity (ME) F: entite de maintenance (EM) S: entidad de mantenimiento (EM) Maintenance entities are defined by the following principles: - The different equipments of the telecommunica- tions network constituting the MEs are interconnected to consecu- tive and easily identifiable interface points, at which points the interface conditions defined for these equipments apply and which possesses the means of detecting maintenance events and failures; - If the telecommunication equipment supports bidirectional transmission, normally consisting of telecommunica- tions equipment trasmitting in both directions, then both direc- tions are considered part of the same ME; - When a failure occurs within a network it is desirable that the maintenance alarm information indication appears at the failed maintenance entity. When this is not practical, the indication should appear at the closest possible entity; - Maintenance alarm information indications in an entity should not cause related alarm information indications at other entities. In the event that such indications are permitted to occur, they should clearly indicate that the failure has occurred upstream, and not in the other entities displaying the information. (Rec. M.20) 82 maintenance entity assembly (MEA) F: assemblage d'entites de maintenance (AEM) S: conjunto de entidades de mantenimiento (CEM) The maintenance entity assembly is defined by the following principles: - An MEA contains a group of MEs assembled for additional maintenance purposes; - Principles that apply to MEs apply also to MEAs; - An MEA may detect failures and maintenance event information which can not be detected by MEs; - An MEA may provide end-to-end maintenance alarm information which can not be provided by MEs. End-to-end information may be collected by using additional supervision means. (Rec. M.20) 83 maintenance sub-entity (MSE) F: sous-entite de maintenance (SEM) S: subentidad de mantenimiento (SEM) The maintenance sub-entity is defined by the following princi- ples: - The different parts of an MSE constituting the MEs are interconnected at consecutive and easily identifiable interface points; - When a failure occurs within an MSE it is desir- able that the maintenance alarm information indication appears at the failed maintenance entity containing the MSE; - A failed MSE should be identified as failed by the fault location process, but should lead only to the identifica- tion of the failed ME by the supervision process; - An MSE generally corresponds to the item which is replaceable during routine operations in the event of failure. (Rec. M.20) 84 maintenance event information (MEI) F: information sur les evenements de maintenance (IEM) S: informacion de evento de mantenimiento (IEM) This information has to be generated as a consequence of events when no immediate actions by the maintenance staff are required, because the total performance is not endangered. The maintenance actions can be performed on a scheduled basis or after the accumulation of maintenance event information indications. (Rec. M.20) 85 maintenance philosophy F: philosophie de maintenance S: filosofia de mantenimiento A system of underlying principles for the organization and execution of the maintenance. (Supplement No 6, Fascicle II.3) 86 maintenance policy F: politique de maintenance S: politica de mantenimiento A description of the interrelationship between the maintenance echelons, the indenture levels and the levels of maintenance to be applied for the maintenance of an item. (Supplement No 6, Fascicle II.3) 87 maintenance service provider (MSP) F: fournisseur de service de maintenance (FSM) S: proveedor de servicios de mantenimiento (PSM) The MSP represents a group of functions, equipment and mainte- nance staff, that together have the responsibility for maintaining the subscriber installation or a part of the subscriber installa- tion. A MSP cannot control the maintenance functions of the sub- scriber access. If authorized, it can request information from the SAMC about the subscriber access. (Rec. M.36) 88 maintenance strategy F: strategie de maintenance S: estrategia de mantenimiento A plan for the organization and execution of maintenance. 89 maintenance support (performance) F: logistique de maintenance S: logistica de mantenimiento The ability of a maintenance organization, under given condi- tions, to provide upon demand the resources required to maintain an item, under a given maintenance policy. Note - The given conditions are related to the item itself and to the conditions under which the item is used and m aintained. (Supplement No 6, Fascicle II.3) 90 management entities F: entites de gestion S: entidades de gestion Management entities are groups of capabilities that collec- tively provide management functions, such as operations, adminis- tration, maintenance and provisioning. For the network part, the functions may be implemented by a combination of capabilities in the network elements and operations systems. For the subscriber part, management functions may be contained within the subscriber installations. (Rec. M.36) 91 measurement F: mesure S: medida; medicion The numerical assessment, in suitable units, of the value of a simple or complex quantity or magnitude. (Rec. M.700, Red Book ) 92 mediation device (MD) F: dispositif de mediation (DM) S: dispositivo de mediacion (DM) The MD is the stand alone device which performs mediation functions (MFs). MDs can be implemented as hierarchies of cascaded devices. (Rec. M.30) 93 mediation function (MF) block F: bloc de fonction de mediation (FM) S: bloque de funciones de mediacion (FM) The MF block acts on information passing between network ele- ment function blocks (NEFs) and operations system function blocks (OSFs) to achieve smooth and efficient communication. Major MFs include communication control, protocol conversion and data han- dling, communication of primitive functions, processes involving decision making, and data storage. Details of the MF are given in S 5.4 of Recommendation M.30. (Rec. M.30) 94 multiterminal service circuit F: circuit de service multiterminal S: circuito de servicio multiterminal A telephone or teleprinter (teletypewriter) service circuit serving more than two stations and having at least one branching point. On each branch of this circuit a certain number of stations can be connected in series. Every station served can enter the cir- cuit individually. See Figure 2/M.100. (Rec. M.100) 95 national main section F: section nationale principale S: seccion principal nacional The whole of the assembly of national group or supergroup sec- tions containing the defined test access points at the terminal national centre and defined test access points at the terminal international centre (see Figure 1/M.900). (Rec. M.900) 96 national system F: systeme national S: sistema nacional This system may comprise one or more 4-wire amplified national circuits with a 4-wire interconnection, and circuits with 2-wire connection to terminal exchanges and subscribers. See Figure 1/M.560. (Rec. M.560) 97 network analysis point F: centre d'analyse du reseau S: punto de analisis de la red The network analysis point is an element within the general maintenance organization for the international automatic and semi-automatic telephone service associated with one or more inter- national centres. It receives information concerning service quality and faults not associated with specific circuits. It analyses all relevant information to investigate the problems involved. It may request the fault report point (network) to initiate investigatory and/or remedial actions in one or more maintenance centres in the home country or via a fault report point (network) in another country. The network analysis point acts as a single point of contact for general enquiries concerning the day-to-day maintenance of the international telephone network, as may be made by the maintenance organizations of other Administrations. (Rec. M.720) 98 network element (NE) F: element de reseau (ER) S: elemento de red (ER) The NE is comprised of telecommunication equipment (or groups/parts of telecomunication equipment) and support equipment that performs network element functions (NEFs) and has one or more standard Q-type interfaces. (Rec. M.30) 99 network element function (NEF) block F: bloc de fonction d'element de reseau (FER) S: bloque de funciones de elemento de red (FER) The NEF block communicates with a telecommunication management network (TMN) for the purpose of being monitored and/or controlled. Details of the NEF are given in S 5.5 of Recommendation M.30. (Rec. M.30) 100 omnibus service circuit F: circuit de service omnibus S: circuito de servicio omnibus A telephone or teleprinter (teletypewriter) service circuit serving more than two stations connected in series, any or all of which may make connection to the service circuit simultaneously. See Figure 1/M.100. (Rec. M.100) 101 operation, administration and maintenance centre (OAMC) F: centre de gestion, d'exploitation et de maintenance (CGEM) S: centro de operaciones, administracion y mantenimiento (COAM) The OAMC is an administration's centre with the responsibility for the general operation, administration and maintenance of the network. It includes both the staff and associated operations sys- tems. The functions may be distributed among many centres and operation systems. (Rec. M.36) 102 operations systems (OS) F: systeme d'exploitation (SE) S: sistema de operaciones (SO) The OS is the stand alone system which performs operation sys- tem functions (OSFs). (Rec. M.30) 103 operations system function (OSF) block F: bloc de fonction de systeme d'exploitation (FSE) S: bloque de funciones de sistema de operaciones (FSO) The OSF block processes information related to telecommunica- tion management to support and/or control the realization of vari- ous telecommunication management functions. Details of the OSF are given in S 5.2 of Recommendation M.30. (Rec. M.30) 104 path; telecommunication path F: itineraire de telecommunications S: trayecto de telecomunicacion The continuous course taken by a transmission signal beween two points. Note 1 - This may be a physical transmission medium, a fre- quency band in a frequency multiplex, a time slot in a time divi- sion multiplex, etc. Note 2 - The path includes the transmission media and the means used for connecting them together. (Rec. Q.9) 105 path; digital path F: conduit; conduit numerique S: trayecto digital The whole of the means of transmitting and receiving a digital signal of specified rate between those two digital distribution frames (or equivalent) at which terminal equipments or switches will be connected. Terminal equipments are those at which signals at the specified bit rate originate or terminate. Note 1 - A digital path comprises one or more sections. Note 2 - Where appropriate, the bit rate should qualify the title. Note 3 - Digital paths interconnected by digital switches form a digital connection. (Rec. M.300) 106 point F: point S: punto a) to identify an element within a maintenance organization where specified functions are carried out. Examples of its use in this context are: fault report point-circuit, restora- tion control point, testing point-transmission; b) to identify an electrical location in a circuit, group, digital path, etc., where access is required for testing purposes. Examples of its use in this context are: circuit access point, analogue link access point, digital path access point. (Rec. M.700, Red Book ) 107 prompt maintenance alarm (PMA) F: alarme de maintenance immediate (AMI) S: alarma de mantenimiento inmediato (AMI) A prompt maintenance alarm is generated in order to initiate maintenance activities (normally immediately) by maintenance per- sonnel to remove from service a defective equipment for the purpose of restoring good service and effecting repair of the failed equip- ment. (Rec. M.20) 108 propagation performance F: caracteristiques de propagation S: caracteristica de propagacion The ability of a propagation medium, in which a wave pro- pagates without artificial guide, to transmit a signal within the given tolerances. Note - The given tolerances may apply to variations in signal level, noise, interference levels, etc. (Rec. E.800) 109 protection switching F: commutation sur liaison de reserve S: conmutacion de proteccion Note - This term was used in the CCITT Red Book and has been deleted in the Blue Book . For more information, see the defini- tions for terms relating to direct transmission restoration (pro- tection link switching) and automatic and semi-automatic transmis- sion restoration (protection network switching) in Recommendation M.495. 110 protected monitoring point F: point de surveillance protege S: punto de monotorizacion protegido A protected monitoring point provides a digital interface at which it is possible to monitor the transmitted signal and to make measurements with suitable test equipments (described in Fascicle IV.4, Red Book ). The degree of protection is considered to be sufficient when a variation of the pulse mask as given in Recommendation G.703 is less than x % with a short circuit at the protected monitoring point. (The value of x is for further study in connection with the electrical characteristics.) Note - The above definition is a working definition and is under study in Study Groups IV and XV. 111 quality of service (QOS) F: qualite de service (QDS) S: calidad de servicio (CDS) The collective effect of service performances which determine the degree of satisfaction of a user of the service. Note - The quality of service is characterized by the com- bined aspects of service support performance, service operability performance, service integrity and other factors specific to each service. See Figure 1/E.800. (Rec. E.800) 112 redundancy, standby F: redondance en attente; redondance passive; redondance en secours S: redundancia pasiva; redundancia de reserva That redundancy wherein one means for performing a required function is intended to operate while the alternative means are inoperative until needed. (Supplement No. 6, Fascicle II.3) 113 reliability (performance) F: fiabilite S: fiabilidad The ability of an item to perform a required function under given conditions for a given time period. Note 1 - It is generally assumed that the item is in a state to perform this required function at the beginning of the time interval. Note 2 - The term reliability is used as a measure of relia- bility performance. (Supplement No. 6, Fascicle II.3) 114 restoration; recovery F: retablissement S: restablecimiento That event when the item regains the ability to perform a required function after a fault. (Supplement No. 6, Fascicle II.3) 113 restoration control point (RCP) F: centre de commande de retablissement du service (CCR) S: punto de control del restablecimiento (PCR) The restoration control point (RCP) is an element within the general maintenance organization for the international telecommuni- cation services. It initiates and coordinates service restoration activities in case of failures or planned outages of transmission systems in accordance with plans and ad hoc arrangements agreed by the technical services of the Administration concerned. (Rec. M.725) 116 routine or periodic testing F: essai de routine ou periodique S: pruebas periodicas; pruebas de rutina Items are tested periodically, initiated either by the system or by the maintenance staff. The frequency of the test depends on the importance of the item, the failure rate and the number of items of that type present in the element. (Rec. M.20) 117 serveability performance F: servibilite (d'un service) S: servibilidad (de un servicio) The ability of a service to be obtained, within specified tolerances and other given conditions, when requested by the user and continue to be provided for a requested duration. Note - Serveability performance may be subdivided into the service accessibility performance and the service retainability performance. (Rec. E.800) 118 service F: service S: servicio A set of functions offered to a user by an organization. (Rec. E.800) 119 service; bearer service F: service support S: servicio portador A type of telecommunication service that provides the capabil- ity for the transmission of signals between user-network inter- faces. (Rec. I.112) 120 service; telecommunication service F: service de telecommunications S: servicio de telecomunicacion That which is offered by an Administration to its customers in order to satisfy a specific telecommunication requirement. Note - Bearer service and teleservice are types of telecom- munication service. Other types of telecommunication service may be identified in the future. (Rec. I.112) 121 service; teleservice F: teleservice S: teleservicio; servicio final A type of telecommunication service that provides the complete compatibility including terminal equipment functions, for communi- cations between users according to protocols established by agree- ment between Administrations. (Rec. I.112) 122 service alarm (SA) F: alarme de service (AS) S: alarma de servicio (AS) A service alarm is generated at maintenance entities at which the service originates and/or terminates to indicate that the par- ticular service is no longer available (e.g., when a primary block is no longer available for setting up connections, the PCM muldex will extend a service alarm indication to the exchange equipment). The service alarm should be generated when performance falls below a level specified for a particular service. This level may coincide with that for initiating also a prompt maintenance alarm. (Rec. M.20) 123 service accessibility performance F: accessibilite (d'un service) S: accesibilidad (de un servicio) The ability of a service to be obtained, within specified tolerances and other given conditions, when requested by the user. Note - This takes into account the transmission tolerance and the combined aspects of propagation performance, trafficability performance and availability performance of the related systems. (Rec. E.800) 124 service integrity F: integrite de service S: integridad del servicio The degree to which a service is provided without excessive impairments, once obtained. Note - This service is characterized by the transmission per- formance of the system. (Rec. E.800) 125 service operability performance F: facilite d'utilisation (d'un service) S: facilidad de utilizacion (de un servicio) The ability of a service to be successfully and easily operated by a user. (Rec. E.800) 126 service retainability performance F: continuabilite (d'un service) S: retenibilidad (de un servicio) The ability of service, once obtained, to continue to be pro- vided under given condition for a requested duration. Note - Generally this depends on the transmission tolerances, the propagation performance and reliability performance of the related systems. For some services, for example packet switching, this also depends on the trafficability performance and the availa- bility performance of the related systems. (Rec. E.800) 127 service support performance F: logistique de service S: logistica del servicio The ability of an organization to provide a service and assist in its utilization. Note - An example of service support performance is the abil- ity to provide assistance in commissioning a basic service, or a supplementary service such as the call waiting service or directory enquiries service. (Rec. E.800) 128 severely errored seconds (SES) F: secondes gravement erronees (SGE) S: segundos con muchos errores (SME) A severly errored second is a second with a binary error ratio [as can be measured using a QRSS (quasi-randon signal source)] greater than or equal to 10DlF2613, or at least one defect (except slips). A pseudo-severely errored second is a second with at least N1 anomalies (when the anomaly is not a binary error, i.e. when it is an error indicator such as a code violation, CRC error, etc.), or one defect (except slips). The value of N1 is an estimator defined to correspond to a BER of 10DlF2613 in one second. N1 is a function of the accuracy of the anomaly detectors. (Rec. M.550) 129 sub-control station F: station sous-directrice S: estacion subdirectora A sub-control station is a point within the general mainte- nance organization which fulfills the sub-control responsibilities of the circuit, group, supergroup, etc., digital section assigned to it. (Rec. M.90) 130 subscriber access maintenance centre (SAMC) F: centre de maintenance d'acces d'abonne (CMAA) S: centro de mantenimiento de accesos de abonado (CMAA) The SAMC represents a group of functions, network equipment elements and staff controlled by the Administration, which together have the responsibility and capability for maintenance functions and maintenance actions within the subscriber access. (Rec. M.36) 131 subscriber access maintenance entity (SAME) F: entite de maintenance d'acces d'abonne (EMAA) S: entidad de mantenimiento de accesos de abonado (EMAA) The SAME controls the subscriber access maintenance functions and provides communications for such activities. The SAME might be distributed. (Rec. M.36) 132 subscriber installation maintenance entity (SIME) F: entite de maintenance d'installation d'abonne (EMIA) S: entidad de mantenimiento de instalaciones de abonado (EMIA) A SIME represents a group of dedicated functions contained within the functional groups (as specified in Recommendation I.411) of the subscriber insallation (i.e. TE1 and NT2) which have the following purposes; e.g. - interaction with the (human) user; - handling of maintenance protocol from the SAME and/or MSP; - control of internal testing and maintenance mechanisms. (Rec. M.36) 133 system availability information point F: service collectant les informations relatives a la disponibilite des systemes S: punto de informacion sobre disponibilidad del sistema The system availability information point is an element within the general maintenance organization for the international automatic and semi-automatic telephone service associated with one or more international centres. It collects and disseminates infor- mation concerning the non-availability of telecommunications sys- tems which affects the international service. The term availability is used here in the broadest sense of the word. (Rec. M.721) 134 telecommunication F: telecommunication S: telecomunicacion Any transmission and/or emission and reception of signals representing signs, writing, images and sounds or intelligence of any nature by wire, radio, optical or other electromagnetic sys- tems. (Recs. G.701, I.112) 135 telecommunication Administration F: Administration des telecommunications S: Administracion de telecomunicaciones An Administration, or the part of a combined postal and telecommunication Administration, concerned with the provision of telecommunication service. (Rec. D.70) 136 telecommunications management network (TMN) F: reseau de gestion des telecommunications (RGT) S: red de gestion de las telecomunicaciones (RGT) A telecommunications management network provides the means used to transport and process information related to management functions for the telecommunications network. (Rec. M.30) 137 terminal international centre F: centre terminal international S: centro terminal internacional The international centre (for example, an international repeater station) serving the renter in the country in which the renter's installation is situated. There will be two terminal international centres in an international leased group or super- group link, or more in the case of a multiterminal link (see Figure 1/M.900) (Rec. M.900) 138 terminal international centre F: centre terminal international S: centro terminal internacional The terminal international centre (TIC) for leased and special circuits is the international centre serving the renter in the country in which the renter's installation is situated. It marks the interface of the international and national lines and is nor- mally located in association with a terminal international centre for the international public telephony circuits. Some Administrations may wish to locate the TIC for interna- tional leased and special circuits indepen dently of that for pub- lic telephony circuits. In all cases there will be a transmission maintenance point (international line) (MTP-IL) (see Recommendation M.1014) located at each TIC for leased and special circuits. There will be two TICs in a point-to-point international cir- cuit. There may be more in a multiterminal circuit. See Figure 2/M.1010. (Rec. M.1010) 139 terminal national centre F: centre terminal national S: centro terminal nacional The nearest national installation (for example, a repeater station) to which the renter's equipment is connected by the termi- nal national section. This centre will normally be staffed and equipped to make transmission measurements (see Figure 1/M.900). (Rec. M.900) 140 terminal national centre F: centre terminal national S: centro terminal nacional The national centre (e.g., repeater station, telephone exchange) that is: - nearest to the renter's installation; - provided with a circuit test point, so that transmission measurements can be made by appropriate staff. See Figure 2/M.1010. (Rec. M.1010) 141 terminal national section F: section nationale terminale S: seccion terminal nacional The lines and apparatus between the defined test access points at the interface in the renter's premises and corresponding defined access points at the terminal national centre (see Figure 1/M.900). (Rec. M.900) 142 terminal national section F: section nationale terminale S: seccion terminal nacional The lines and apparatus connecting the renter's installation with the terminal national centre concerned. There may be inter- mediate installations (e.g., telephone exchanges) in the terminal national section but they are assumed to have no testing facilities normally available. See Figure 2/M.1010. (Rec. M.1010) 143 test F: essai S: prueba A direct practical trial in whatever manner it may be made. (Rec. M.700, Red Book ) 144 test; functional test F: essai de fonctionnement S: prueba de funcionamiento A yes or no test made to indicate whether a circuit, equipment or part of an equipment will function or not function under actual working conditions. (Rec. M.700, Red Book) 145 test; limit test F: essai aux limites S: prueba en los limites A test made to indicate whether a quantity would fall within or outside a pair of limits or boundaries. (Rec. M.700, Red Book) .bp 146 test; yes or no test F: essai par "tout ou rien" S: prueba de viabilidad A test made to indicate whether a quantity or magnitude would fall above or below a specified limit or boundary defined to dis- tinguish pass and fail conditions. (Rec. M.700, Red Book) 147 testing point (line signalling) F: centre pour les essais de la signalisation de ligne S: punto de pruebas de la se~alizacion de linea The testing point (line-signalling) is an element within the general maintenance organization for the international automatic and semi-automatic telephone service at each international centre. It carries out line signalling tests on international circuits using channel-associated signalling systems, e.g., R2, No. 5, whether provided by wholly analogue transmission and switching sys- tems or by a mixture of analogue and digital systems. Note - In practice, at digital international exchanges, a line access point at the circuit level may not exist when the exchanges is interfaced by primary (or higher order) digital paths. Thus, all signalling testing may need to be carried out from one location - generally the testing point (switching and interregister signalling). Signalling tests on Signalling System No. 6 are con- trolled and coordinated by the administrative control (see Recommendation M.762). (Rec. M.718) 148 testing point (switching and interregister signalling) F: centre pour les essais de commutation et de la signali- sation entre enregistreurs S: punto de pruebas de conmutacion y se~alizacion entre registradores The testing point (switching and interregister signalling) is an element within the general maintenance organization for the international automatic and semi-automatic telephone service at each international centre. It carries out tests concerned with switching and interregister signalling functions associated with international circuits, whether provided by wholly analogue transmission and switching systems or by a mixture of analogue and digital systems. Note - In practice, at digital international exchanges, a line access point at the circuit level may not exist when the exchange is interfaced by primary (or higher order) digital paths. Thus, all signalling testing may need to be carried out from one location, generally the testing point (switching and interregister signalling). This would include line signalling aspects, if any. (Rec. M.719) 149 testing point (transmission) F: centre pour les essais de la transmission S: punto de pruebas de la transmision The testing point (transmission) is an element within the gen- eral maintenance organization for the international automatic and semi-automatic telephone service at each international centre. It carries out transmission testing on international circuits whether provided by wholly analogue transmission and switching systems or by a mixture of analogue and digital systems. (Rec. M.717) 150 trafficability performance F: traficabilite; capacite d'ecoulement du trafic S: aptitud para cursar trafico The ability of an item to meet a traffic demand of a given size and other characteristics, under given internal conditions. Note - Given internal conditions refer, for example, to any combination of faulty and non-faulty sub-items. (Rec. E.800) 151 transmission F: transmission S: transmision The action of conveying signals from one point to one or more other points. Note 1 - Transmission can be effected directly or indirectly, with or without intermediate storage. Note 2 - The use of the English word "transmission" in the sense of emission is deprecated. (Recs. G.701, I.112) 152 transmission performance F: qualite de transmission S: calidad de transmision The level of reproduction of a signal offered to a telecommun- ications system, under given conditions, when this system is in an up state. (Rec. E.800) 153 transmission restoration F: retablissement de la transmission S: restablecimiento de la transmision The different actions taken in order to restore the transmis- sion of a signal affected by a transmission fault. (Rec. M.495) 154 transmission route F: trajet de transmission S: ruta de transmision A transmission facility on a specific medium used by a certain number of transmission systems between two stations. Note 1 - For example, one cable between two stations could be regarded as one transmission route (whatever the number of systems using this cable is) and a radio system between these two points could be regarded as another route. Note 2 - This represents a physical route; this is different from the term "route" which is defined in the E.600, Q.9 and Z.341 Recommendations, which represents a logical route. (Rec. M.495) 155 transmission route diversity F: diversite de routage de transmission S: diversidad de rutas de transmision The provision of at least two links between two nodes in a transmission network which are routed over different transmission routes. Note - In case of a failure of one link, transmission route diversity allows some traffic between the two nodes still to be carried over the remaining link(s). (Rec. M.495) 156 upstream failure indication (UFI) F: indication de defaillance en amont (IDA) S: indicacion de fallo atras (IFA) The upstream failure indication given by a maintenance entity indicates that the signal arriving at that maintenance entity is defective. The UFI indicates that the failure has occurred upstream of this point and no unnecessary maintenance activities are initiated. (Rec. M.20) ANNEX A (to Recommendation M.60) List of maintenance terms This Annex presents the maintenance terms in alphabetical order together with their section number. Section No. Term 1 Alarm indication signal (AIS) 2 Anomaly 3 Automatic switching equipment 4 Availability (performance) 5 Bit error ratio (BER) 6 Bridging loss 7 Channel; access channel 8 Channel; transmission channel 10 Circuit; digital circuit 9 Circuit; telecommunication circuit 11 Circuit access points 12 Circuit control station 13 Circuit sub-control station 14 Code violation 15 Connection 16 Connection; digital connection 17 Connection; international connection 18 Connection; international telephone connection 19 Continuity check 20 Continuous checking 21 Control station 22 Data communication network 23 Data communications network (DCN) 24 Data communications function (DCF) 25 Dead time 26 Defect 27 Deferred maintenance alarm (DMA) 28 Degraded minute (DM) 29 Echo 30 Echo canceller 31 Echo suppressor 32 Error 33 Error; random error 34 Error burst 35 Error free seconds (EFS) 36 Errored seconds 37 Exchange 38 Failure 39 Fault 40 Fault; intermittent fault Section No. Term 41 Fault correction 42 Fault localization; localization of faults 43 Fault report point (circuit) 44 Fault report point (network) 45 Interface 46 International automatic circuit 47 International chain 48 International leased circuit 49 International main section 51 Interruption 52 Interruption 50 Interruption; break of service 53 Line; international line 54 Line; international line 55 Line; national line 56 Line access point 57 Link; international link 58 Link; transmission link 59 Logistic delay 60 Loopback 61 Loopback; complete loopback 62 Loopbback; digital loopback 63 Loopback; logical loopback 64 Loopback; non-transparent loopback 65 Loopback; partial loopback 66 Loopback; transparent loopback 67 Loopback application 68 Loopback control mechanism 69 Loopback control point 70 Loopback point 71 Loopback requesting point 72 Loopback test pattern 73 Maintainability (performance) 74 Maintenance 75 Maintenance 76 Maintenance; automatic maintenance 77 Maintenance; controlled maintenance 78 Maintenance; corrective maintenance 79 Maintenance; deferred maintenance 80 Maintenance; preventive maintenance Section No. Term 81 Maintenance entity (ME) 82 Maintenance entity assembly (MEA) 84 Maintenance event information (MEI) 85 Maintenance philosophy 86 Maintenance policy 87 Maintenance service provider (MSP) 88 Maintenance strategy 83 Maintenance sub-entity (MSE) 89 Maintenance support (performance) 90 Management entities 91 Measurement 92 Mediation device (MD) 93 Mediation function (MF) (block) 94 Multiterminal service circuit 95 National main section 96 National system 97 Network analysis point 98 Network element (NE) 99 Network element function (NEF) block 100 Omnibus service circuit 101 Operation, administration and maintenance centre (OAMC) 102 Operations system (OS) 103 Operations system function (OSF) block 105 Path; digital path 104 Path; telecommunication path 106 Point 107 Prompt maintenance alarm 108 Propagation performance 110 Protected monitoring point 109 Protection switching 111 Quality of service (QOS) 112 Redundancy; standby 113 Reliability (performance) 115 Restoration control point 114 Restoration recovery 116 Routine or periodic testing 117 Serveability performance 118 Service 119 Service; bearer service Blanc Section No. Term 120 Service; telecommunication service 121 Service; teleservice 123 Service accessibility performance 122 Service alarm (SA) 124 Service integrity 125 Service operability performance 126 Service retainability performance 127 Service support performance 128 Severely errored seconds (SES) 129 Sub-control station 130 Subscriber access maintenance centre (SAMC) 131 Subscriber access maintenance entity (SAME) 132 Subscriber installation maintenance entity (SIME) 133 System availability information point 134 Telecommunication 135 Telecommunication Administration 136 Telecommunications management network (TMN) 137 Terminal international centre 138 Terminal international centre 139 Terminal national centre 140 Terminal national centre 142 Terminal national section 142 Terminal national section 143 Test 144 Test; functional test 145 Test; limit test 146 Test; yes or no test 148 Testing point (switching and interregister signalling) 149 Testing point (transmission) 147 Testing point (line signalling) 150 Trafficability performance 151 Transmission 152 Transmission performance 153 Transmission restoration 154 Transmission route 155 Transmission route diversity 156 Upstream failure indication (UFI) Blanc MONTAGE: PAGE 110 = PAGE BLANCHE