Describing Layered Communication Architecture in SDL Markup Language

Using Specification and Description Language (SDL) as a formal language for specification of requirements for the complex, real-time and distributed systems involving many concurrent activities, we have come to the idea of making the language independent of platforms and operating systems which may use it. Shortly, we have developed markup version of the SDL language, and named it SDL Markup Language. It is an XML-based version of the SDL-PR (Phrase Representation), an SDL textual notation. We use the language to specify the complex communications protocols, which are used in wide range of layered architectures. We provide the specification from the INRES protocol in SDL-ML

Automated enrichment of SDL specifications with MSCs

Formal methods and Formal Description Techniques (FDT) are becoming more and more important for developing complex real-time and distributed systems. Message Sequence Charts (MSC) and Specification and Description Language (SDL) are standardized FDTs for specification of telecommunication protocols in particular and distributed systems in general. We present an automated approach for enriching an SDL specification with MSC. This approach can be used for incremental development with SDL and MSC or for maintenance of a system in SDL. Enrichment of SDL with MSC involves enrichment of SDL architecture and behavior. Our automated approach consists of three interconnected steps i.e. pre-phase, MSC2SDL phase and post-phase . In the pre-phase SDL architecture is enriched using new MSC. We give algorithms for enriching SDL architecture using MSC. MSC2SDL phase generates new SDL behavior using new MSC and enriched architecture. This phase uses MSC2SDL tool. Finally, the post-phase merges old and new SDL behavior to get enriched SDL. We have developed 14 rules of behavioral merger based upon a formal extension relation which guarantees to preserve all the old behavior and prevents introduction of new non-determinism in the enriched specifications. Furthermore, we have developed tools for pre-phase and post-phase and they have been connected with MSC2SDL tool to get a tool set for automated enrichment

The pros and cons of using SDL for creation of distributed services

In a competitive market for the creation of complex distributed services, time to market, development cost, maintenance and flexibility are key issues. Optimizing the development process is very much a matter of optimizing the technologies used during service creation. This paper reports on the experience gained in the Service Creation projects SCREEN and TOSCA on use of the language SDL for efficient service creation

Finite state machine based SDL

No abstract available

The formal, tool supported development of real time systems

The language SDL has long been applied in the development of various kinds of systems. Real-time systems are one application area where SDL has been applied extensively. Whilst SDL allows for certain modelling aspects of real-time systems to be represented, the language and its associated tool support have certain drawbacks for modelling and reasoning about such systems. In this paper we highlight the limitations of SDL and its associated tool support in this domain and present language extensions and next generation real-time system tool support to help overcome them. The applicability of the extensions and tools is demonstrated through a case study based upon a multimedia binding object used to support a configuration of time dependent information producers and consumers realising the so called lip-synchronisation algorithm

Creating telecommunication services based on object-oriented frameworks and SDL

This paper describes the tools and techniques being applied in the TINA Open Service Creation Architecture (TOSCA) project to develop object-oriented models of distributed telecommunication services in SDL. The paper also describes the way in which Tree and Tabular Combined Notation (TTCN) test cases are derived from these models and subsequently executed against the CORBA-based implementations of these services through a TTCN/CORBA gateway

Towards more accurate real time testing

The languages Message Sequence Charts (MSC) [1], System Design Language1 (SDL) [2] and Testing and Test Control Notation Testing2 (TTCN-3) [3] have been developed for the design, modelling and testing of complex software systems. These languages have been developed to complement one another in the software development process. Each of these languages has features for describing, analysing or testing the real time properties of systems. Robust toolsets exist which provide integrated environments for the design, analysis and testing of systems, and it is claimed, for the complete development of real time systems. It was shown in [4] however, that there are fundamental problems with the SDL language and its associated tools for modelling and reasoning about real time systems. In this paper we present the limitations of TTCN-3 and propose recommendations which help minimise the timing inaccuracies that would otherwise occur in using the language directly

Experiences modelling and using object-oriented telecommunication service frameworks in SDL

This paper describes experiences in using SDL and its associated tools to create telecommunication services by producing and specialising object-oriented frameworks. The chosen approach recognises the need for the rapid creation of validated telecommunication services. It introduces two stages to service creation. Firstly a software expert produces a service framework, and secondly a telecommunications ‘business consultant' specialises the framework by means of graphical tools to rapidly produce services. Here the focus is given to the underlying technology required. In particular, the advantages and disadvantages of SDL and tools for this purpose are highlighted

Architecting specifications for test case generation

The Specification and Description Language (SDL) together with its associated tool sets can be used for the generation of Tree and Tabular Combined Notation (TTCN) test cases. Surprisingly, little documentation exists on the optimal way to specify systems so that they can best be used for the generation of tests. This paper, elaborates on the different tool supported approaches that can be taken for test case generation and highlights their advantages and disadvantages. A rule based SDL specification style is then presented that facilitates the automatic generation of tests

Frameworks: the future of formal software development?

It could be argued that the primary issue to be dealt with in software engineering today is re-use of software. Current software development rarely, if ever, starts from nothing. Unfortunately, the same cannot be said for the development of specifications. To overcome this problem, various works have attempted to show how specifications can be built using architectural principles. We discuss one such approach in particular, the Architectural Semantics of Open Distributed Processing. We show the limitations of this work with regard to the architecting of specifications and propose a new approach, based on frameworks. To highlight the approach we use the work currently being done in the TOSCA project in its development of a service creation and validation environment for telecommunication services