============================================================ Question 1/X - Reorganization and extension of existing Recommendations Z.311 to Z.323 Considering - that Recommendations Z.311-Z.317 are not changing with respect to TTYs; - that Recommendations Z.321-Z.323 are changing in order to keep pace with current technology; - that basing Recommendations Z.321-Z.323 on Recommendations Z.311Z.317 leads to many problems, exceptions, special cases, etc. when attempting to implement these Recommendations; - that the use of graphics, windowing techniques, screen layouts and associated reference models cannot be fully exploited under the current structure of Recommendations, How should the existing Recommendations Z.311-Z.323 be reorganized and extended to allow maximum utilization of new VDT technologies? Note - Close collaboration is required with Study Group IV, IEC and ISO. ANNEX (to Question 1/X) Identical to the annex to Question 2/X ============================================================ Question 2/X - New Recommendations and maintenance of existing Recommendations to account for centralized environments Considering - that Recommendation Z.301 states that the Recommendations of the Z.300-Series apply equally to centralized as well as local environments; - that under the current Recommendations, it is not clear how some functions (e.g. user identification) can be implemented in a centralized environment; - that the evolution of telecommunication networks points to an ever- increasing role played by centralized environments, What new Recommendations and/or changes to existing Recommendations are needed such that both local and centralized environments are fully supported for all man-machine interface applications? Note - Close collaboration is required with Study Group IV, IEC and ISO. ANNEX (to Question 2/X) Standardization of operation and maintenance centres (OMC) and MML commands supplied by different manufacturers Abstract Experience indicates that in a country with sufficiently large demand, there is a tendency to have more than one switching system in service, and that, due to the advantages of centralized operation and maintenance in a digital switching system, administrations are going to introduce OMC in their network. The CCITT should therefore consider the matter in order to enable telecommunication administrations to utilize a single OMC and operators command code for different systems. Introduction In order to maintain competition between suppliers and to prevent a single manufacturer from monopolizing the market, telecommunication administrations intend to use at least two digital switching systems manufactured by different companies. At the moment, an OMC offered by one supplier cannot be utilized to maintain and control a local/transit digital switching system manufactured by another supplier. In order to have unified OMC in the network and to facilitate maintenance outside existing interface standards, there should be a Recommendation to unify OMC software, especially with regard to input/output format. Moreover, despite the availability of a command list manual according to MML rules by different manufacturers, command codes differ from one supplier to another. The following is an example of creating a subscriber in two systems, A and B: System A --> CR SUB: DN = XXX, EQN = XXX, SCOS = XXX, ... System B --> SOD : N = XXX, EL = XXX, LC = XXX, ... In both systems, commands are used for the same purposes. Proposal It is proposed that in drawing up Recommendations the CCITT should consider the following objectives: 1) defining a standard OMC with the required facilities and unifying the necessary functions with a view to providing administrations with a unique OMC for maintaining and controlling different switching systems supplied by different manufacturers; 2) unifying all command codes which are not system-dependent. ============================================================ Question 3/X - Supplementing international standardization work to enhance the use of CCITT MML in interfacing to telecommunication networks Considering - that the centralization of operations and maintenance jobs is increasing, leading to the same operator controlling several systems (and/or several applications) by using only one terminal; - that the distance between operators and the systems they control is increasing, leading to the increased use of telecommunications networks to access those systems; - that the use of sophisticated and complex software tools leads to improved operations conditions and more efficient and ergonomic man- machine dialogues; - that the technological advances in terminals, workstations, etc. are leading towards more powerful systems and networks; - that MML Recommendations Z.301-Z.323 provide Recommendations for user interfaces to telecommunications systems and networks; - that ISO currently has work items on virtual terminals and on terminal management; - that currently there are no CCITT Recommendations in the areas of functions to be implemented on intelligent workstations, the objects to be manipulated on those workstations, nor for the methods by which to manage such objects; - that Recommendations exist on the capabilities of advanced terminals and specification of functions, and that the extension of this work to intelligent workstations is needed; - what new Recommendations and extensions to existing Recommendations are needed to supplement the international standardization work such that CCITT MML can be fully utilized in interfacing to telecommunication networks? ANNEX (to Question 3/X) Identical to the annex to Question 2/X ============================================================ Question 4/X - Improved methodology to specify Human-Machine Interface (HMI) Considering (a) that there is a need for improved communication of the HMI specifications between end-users and designers and between humans and systems, enabling the identification of the data structures to be managed by the HMI; (b) that HMI development methods need to be adjusted to cover new technologies, new application areas and new ways of working; (c) that both end-users and designers would benefit from a common overview of the HMI specifications provided by a reference model; (d) that both end-users and designers must share a common understanding of the implications of HMI specifications; (e) that the improved HMI methodology to specify, when tested and successfully demonstrated, may necessitate revisions and/or replacements of current Z.300-Series Recommendations; (f) that Recommendation Z.100, defining completely the Specification and Description Language (SDL) and Recommendation Z.110 providing guidelines for the application of FDT, are available and standardized techniques on information modelling exist; (g) that work on reference models is progressing within CCITT, 1. What new Recommendations for improved HMI specification techniques should be provided, including: - formalism, - methods, - reference model, - testing, demonstration and guidance for usage? 2. What revisions and/or replacements of current Z.300-Series Recommendations, due to improved HMI specification techniques, should be provided? ANNEX (to Question 4/X) Identical to the annex to Question 2/X ============================================================ Question 5/X - Specification of the Human-Machine Interface to support the management of telecommunication networks Considering (a) that there are Recommendations in the Z.300-Series which cover the areas of input syntax, output syntax, dialogue procedures and methodology for the specification of the man-machine interface both for teleprinter terminals and for advanced visual display terminals; (b) that there are Recommendations in the Z.300-Series which already cover the specification of MML function semantics in the area of Subscriber Administration, Routing Administration, Traffic Measurement Administration, Network Management Administration; (c) that new Human-Machine Interface (HMI) specification techniques are expected to be developed; (d) that in the specification of the Human-Machine Interface expertise not only in the relevant functional areas, but also in HMI techniques is essential, 1. What new Recommendations and/or modifications to existing Recommendations should be provided for the Human-Machine Interface to support the administration of: - routing, - tariff and charging, - traffic, - system control, - .........? 2. What new Recommendations and/or modifications to existing Recommendations should be provided for the Human-Machine Interface to support the Access Control Administration? 3. What new Recommendations and/or modifications to existing Recommendations should be provided for the Human-Machine Interface to support the Network Management Administration? 4. What new Recommendations and/or modifications to existing Recommendations should be provided for the Human-Machine Interface to support the maintenance of Telecommunication Networks? 5. What new Recommendations and/or modifications to existing Recommendations should be provided for the Human-Machine Interface to support the Installation and Testing Functions? 6. What revisions and/or replacements of relevant Recommendations in the Z.300-Series are needed? Note - Close collaboration is required with Study Group IV. ANNEX (to Question 5/X) Identical to the annex to Question 2/X ============================================================ Proposed new Question 6/X - Support environment for telecommunication systems through their lifetimes (Continuation of Question 6/X of the 1985-1988 study period) Considering (a) that telecommunications networks are complex, large, long-lived and evolving; (b) that the quality of telecommunications systems is of paramount importance; (c) that responsibilities between administrations, recognized private operating agencies and suppliers may be shared in many ways; (d) that administrations and recognized private operating agencies may incorporate telecommunications systems from various suppliers into networks, each with its own support facilities, respectively application dependent support systems for various telecommunication systems; (e) that administrations, recognized private operating agencies and suppliers require a set of unified facilities that are effective, economical, reliable, portable and user-friendly in supporting these systems; (f) that there are activities inside and outside CCITT leading towards reference models and integrated computer based environments for the support facilities needed for telecommunications systems; (g) that for ergonomic and economic reasons there is a need for harmonization of support environments; (h) that there is a need to avoid the emergence of conflicting standards; and (i) that CCITT Recommendations and/or Questions exist on Formal Description Techniques (SDL), Programming Language (CHILL) and Man- Machine Language (MML) coordinated use of these languages will be enhanced by unified support facilities, What Recommendations, requirements, or other provisions should apply to support facilities, in particular: a) a reference model for the various aspects of support for telecommunications systems, b) software quality aspects of telecommunications systems, c) terminology? What guidelines, Recommendations, requirements or other provisions should apply to support facility products, in particular: d) use of the Reference Model with respect to systems support environments (for example, use may include planning, construction and assessment of system support environments), e) interfaces to and within systems support environments with regard to human factor principles and the reference model, f) the use of recommended formal description techniques, programming languages, and man-machine languages within systems support environments? Note - This Question should be studied in close cooperation with IEC and ISO, especially with respect to studies going on in parallel in those standardization bodies (e.g., software quality). ANNEX 1 (to Question 6/X) Status of work on Question 6/X at the end of the 1985-1988 study period - Version 5.0 (See Contribution COM X-3) ============================================================ Question 7/X - Software quality, software testing and verification for telecommunication systems Considering - that in the last 20 years we have witnessed an ever-growing incorporation of software into converging telecommunication systems; - that maintaining a high quality of service now implies the correctness of a growing number of software modules which may interact in an open systems interconnection environment; - that software may contain inherent faults and these faults can cause interruptions in the service; - that methods and procedures are being developed as to specifications testing and verification of software related to open systems interconnections; - that administrations, RPOAs and large users are involved in the evaluation of telecommunications software alternatives, whether developed in their own research and development programmes, offered by outside suppliers, or available wholly or in part in CCITT Recommendations, as well as in ISO and IEC standards; decides to study the following Question: What studies, Recommendations or other provisions, if any, are appropriate for: i) testing and verification methods applicable to telecommunications software; and ii) uniform minimum acceptable requirements for a high quality of telecommunications software? What concepts, terms, definitions and measures should be used to measure the correct performance of telecommunications software? What models are recommended to assess the correct performance of telecommunications software with respect to specified parameters or erroneous data? Note - This Question should be studied in close collaboration and cooperation with ISO, IEC and other standardization bodies working on the matter. ============================================================ Question 8/X - Maintenance of SDL (Continuation of Question 1/X studied in 1985-1988) Considering that (a) SDL is now completely defined in Recommendation Z.100 and that revisions might become necessary to fix future detected problems; (b) several tools are available to support various aspects of language application and that several others are under development, so that it is absolutely required to keep the language stable to avoid invalidating existing tools wasting significant economic investment, and to foster new tool development; (c) educational material is available, but it should continue to be updated and improved; (d) the user community is very large and support is required, with particular attention to the application of SDL by other CCITT Study Groups; (e) the number of specifications based on SDL is very large and keeps growing, and the stability of the language is required to avoid invalidating existing specifications; (f) SDL is currently used mostly to support informal specification but its capabilities allow also the support of formal specification which would result in derived benefits in the implementation of system their testing and exploitation; (g) evolution in the application of the language and in the target area might require language enhancement; (h) cooperation has been established with ISO and effective results gained and that work in the area of FDT will continue within ISO; (i) it is important to users of SDL that misinterpretation of Z.100 is avoided to achieve conformance of implemented systems with their specifications and also to prevent proliferation of dialects of the language, What new Recommendations, changes to existing Recommendations, requirements, or other provisions are required for: 1. Z.100 Maintenance, 2.support of SDL Users (including aspects of integration of SDL specifications with specifications produced in natural informal language, in LOTOS or others), 3. furthering the use of formal specification, 4. collaboration with ISO, 5.ensuring that the use of Z.100 is in compliance with the Recommendation? ANNEX (to Question 8/X) Introduction In order to promote the usage of SDL, it must be kept stable. Stability will allow the implementation of tools, educational material and the use of SDL within industrial projects. It is essential that a list of changes is maintained during the next study period, instead of formulating new drafts of the Recommendation text which tends to hide minor changes. At the end of the study period, the list of changes or a new Recommendation text will be issued, as appropriate. In the following, guidelines are proposed which prescribe how SDL should be maintained in the next study period. Terminology - An error is an internal inconsistency within Z.100. -An open item is a problem identified but not solved during the past study period. The open items from the 1984-1988 study period are: -delay on channels; - explicit constructs for non determinism in SDL; - transformation of labels in shorthand notations. -A deficiency occurs when during actual usage, the Z.100 is found to be deficient. Rules for maintenance 1. When an error is detected in Z.100, it must be corrected. The correction of an error should imply as small a change to the language as possible. 2. Except for error corrections and solutions to open items, changes to SDL may only be considered as a result of a formal request for solution of a problem by a substantial user community (e.g. another Study Group within the CCITT). The SDL group should first look for a solution within the existing language. 3. All changes not resulting from an error correction of the language must be extensions, which do not invalidate existing SDL 1988. 4. During the study period all changes are recorded in a "Master List of Changes". This list covers both Z.100 and its annexes (e.g. the User Guidelines and the Formal Definition). No new version of Z.100 will be issued until the end of the study period. 5. If the definition given in Z.100 is deficient, the formal definition (Annex F) must be consulted. Deficiencies in Z.100 are recorded in an "Interpretation Document". At the end of the study period, items from this document may be considered in order to make the language definition more complete. ============================================================ Proposed new Question 9/X - Specification and description techniques needed for telecommunication systems (Continuation of Question 2/X, studied in 1985- 1988) Considering that (a) SDL has been recommended for the functional specification and description of telecommunication systems and is widely used; (b) studies on "future specification and description techniques for telecommunication systems" and "formal description techniques" led to the conclusion that new description techniques should be subject to the criteria of: - need, -evidence that the new technique is based on a significantly different model from that of SDL, -demonstrated usefulness and capabilities of the formal description technique; (c) LOTOS has been standardized by ISO and has been used for OSI specifications, but is subject to enhancement (such as the addition of a graphical representation) following user experience; (d) SDL experts have a considerable experience with a graphical syntax, and initial work has been carried out on a graphical LOTOS syntax in close cooperation with ISO experts, producing a common working document; (e) through the cooperation with ISO experts on formal description techniques in the study period 1985-1988 mutually beneficial harmonization has been achieved (common abstract data type kernel, "Guidelines for the Application of Estelle, LOTOS and SDL"); (f) there are existing needs, and future needs are anticipated for specification and description techniques in CCITT, What further Recommendations or other provisions should apply to specification and description techniques for telecommunications systems, in particular: 1) specification and description of aspects of telecommunications systems in areas not covered by SDL, 2) further application of specification and description techniques such as to modelling, simulation, performance evaluation, and comparison between specifications, descriptions and implementations, 3) further harmonization with techniques of other standardization bodies having similar or mutual interests with CCITT? ============================================================ New Question 10/X - Quality assurance, testing and verification for telecommunications specifications (Continuation of Question 8a/X, studied in 1985-1988) Considering that - current specifications contain errors, and a more systematic approach to quality assurance, testing and verification of telecommunications specifications is required; - the use of Formal Description Technques (FDTs) is a necessary first step towards improvement of the quality of specifications; - FDTs are a possible starting point for tools, quality assurance, testing and verification for various stages from specifications to high level design and implementation (e.g., automatic generation of test sequences from Formal Descriptions); - SDL and other FDTs are now available in stable standards, and studies can be extended to application aspects of FDTs; - many CCITT Study Groups are now involved in applying FDTs to their Recommmendations, and are interested in quality assurance, testing and verification of their Recommendations; - harmonization with other standardization bodies is important to avoid conflicting standards and for effective work. Cooperation has been established with ISO on FDTs, testing and verification, What Recommendations or other provisions should apply for formal approaches to general quality assurance, testing and verification methods for telecommunications specifications? ============================================================ Question 11/X - Harmonization of the use of SDL and CHILL Introduction The proposal is a single Question for the harmonization of the use of SDL and CHILL. The rationale in the Question is that many users use both techniques in one methodology. 1. Harmonization of the use of SDL and CHILL Considering (a) that SDL has been recommended and is widely used for the functional specification and description of telecommunications systems, and that SDL is now a rigorously defined language which offers a basis for defining CCITT Recommendations in a formal or informal way; (b) that CHILL has been recommended and is widely used as the programming language for telecommunications systems; (c) that SDL and CHILL are widely used together in an overall methodology for support of telecommunications systems; (d) that there are major benefits to administrations, recognized private operating agencies and system suppliers in keeping SDL and CHILL stable, and providing suitable material for guidance and education in the use of SDL and CHILL, What new Recommendations, or changes to existing Recommendations, requirements, or other provisions are required to: 1) promote and support the harmonized use of SDL and CHILL ensuring that such use is in compliance with the Recommendations, 2) exploit the capabilities of the languages in combination, in particular the ability of SDL to support formal specification, the relationships between the languages, and the data abstraction in CHILL, 3) give guidelines for methods related to the various coordinated uses of SDL and CHILL? ============================================================ Question 12/X - Maintenance, training, compliance and promotion aspects of CHILL (Continuation of Question 3/X, studied in 1985-1988) Considering (a) that CHILL was designed to be the optimum programming language for telecommunications; (b) that many operating organizations have installed or are planning to instal SPC telephone exchanges incorporating CHILL programmes conforming to Recommendation Z.200 and that CHILL is also suitable for programming other applications in telecommunications; (c) that experience has already been gained by many organizations in the implementation and use of CHILL; (d) that this widespread use of CHILL could result in the detection and the need for correction of deficiencies in Recommendation Z.200 or related documents; (e) that it is very important to keep the language as defined in Recommendation Z.200 stable; (f) that many people from various backgrounds will be involved in the use of CHILL and therefore will need suitable material for training in CHILL; in particular, it is important that the Users Manual reflects Recommendation Z.200; (g) that it is of paramount importance to users to avoid misinterpretation of Recommendation Z.200 in order to achieve conformance of programmes to Recommendation Z.200, What Recommendations, requirements or other provisions should apply to: a) the maintenance of Recommendation Z.200 and related documents, b) training in the use of CHILL, c) means of ensuring that the use of CHILL is in compliance with Recommendation Z.200, d) the promotion of CHILL in the applications where it is found to be suitable? ANNEX (to Question 12/X) List of open items 1.