ITU: Recommendation Z. 120: Message Sequence Chart (MSC). ITU, Geneva, 1996.  Home/Search   Document Not in Database   Summary   Related Articles   Check

....class of transition connected HMSCs. 1 Introduction Message sequence charts (MSCs) are a popular visual formalism for specifying the communication of asynchronous processes, where most of the details (variables, timing constraints, etc) are abstracted away. They are part of the ITU standard [14]. High level message sequence charts (HMSCs) extend MSCs by allowing iteration and non deterministic choices. In this way in nite sets of MSCs can be described. Due to the abstract nature of HMSCs, the question of realizability (or implementability) arises: Given an HMSC (the speci cation) is ....

ITU. Recommendation Z.120. Message Sequence Charts. 1996.

....jitter. With this, definition of response times is possible, but constraining the behaviour of the system environment in a worst case manner remains unsolved. The later problem is addressed in PMSCs [FLMTS97] Again annotations in comments or text symbols, but now to Message Sequence Charts (MSC [ITU94b] are used to express performance requirements . So called tra#c sources allow the specification of inter arrival times of system stimuli. Durations and spans between marks on the MSC time axis are provided for timing constraint specification. PMSCs may be used as basis for an analysis to ....

ITU--T. ITU--T Recommendation Z.120: Message Sequence Chart (MSC),

....and those that are forbidden. LSCs thus extend classical message sequence charts, which do not make such distinctions. The Unified Modeling Language (UML) 33] which is the leading standard for specifying object oriented software systems, uses a variant of classical message sequence charts (MSCs) [21], called sequence diagrams, which can be viewed as a simple existential variant of LSCs. A new approach for capturing behavioral requirements (proposed briefly in [12] has been developed recently, and is described in detail in [14] In it the user plays in the behavior using a graphical ....

ITU. ITU-T recommendation Z.120: Message sequence chart (MSC).

....we do not mark states or transitions with public, assuming that an intruder can either manipulate the complete behaviour of a component or not manipulate it at all. Extended Event Traces Extended Event Traces (EETs) in AutoFocus represent system runs, similarly to message sequence charts [ITU96]. We will use EETs to represent test sequences showing the communication behaviour for a test scenario. In general, input expressions can also use pattern matching, de ned as an abbreviation for an extended precondition and a substitution for the pattern variables. 5 Security Requirements In ....

ITU. ITU-TS Recommendation Z.120: Message Sequence Chart (MSC). ITU-TS, Geneva, 1996.

....is to be achieved by its components. This difficult engineering problem has been studied by many researchers in the last few decades. Those research efforts have led to the definition of different techniques and methods in the area of modeling and design ( 10] 11] 13] 17] 18] 36] 40] [44], 46] 47] 51] 74] 83] 87] 93] simulation ( 10] 23] 68] verification ( 10] 40] 41] and testing ( 10] 14] 77] In the last decade, the object oriented paradigm has emerged as a leading development technology in the real time system industry. This paradigm allows ....

....also allows for the explicit description of concurrency and interactions between scenarios. The use of UCM in industrial projects indicates that it is a powerful technique for modeling complex systems. The UCM modeling technique is supported by the UCM navigator tool [65] The ITU standard MSC [44] is a modeling technique that allows the description of system scenarios in terms of sequences of messages exchanged between system components, and between the system and its environment. This modeling technique is widely used in the industry, and is implemented in many CASE tools. ROOM [93] ....

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ITU (1996). Message Sequence Charts (MSC'96). Recommendation Z.120. Geneva.

....component behavior, and inheritance. This enables designers to concentrate on different issues at different times. Models used in current methodologies include CRC cards ( 8] use cases ( 13] 47] UCM (Use Case Maps) 18] interaction diagrams ( 13] 47] MSC (Message Sequence Charts) [43], 93] different types of structure models ( 13] 93] hierarchical state machines ( 13] 36] 83] 93] activity diagrams ( 13] and class hierarchy models ( 13] 83] Another important aspect of object oriented methodologies is that they are well adapted to iterative development. The ....

....in interaction diagrams, and 2 traceability between objects contained in different models, e.g. objects contained in the analysis model and objects contained in the design model. In a similar context, Andersson and Bergstrand [5] define a traceability relationship between use cases and MSCs [43], and they suggest using SDL for system modeling. However, they do not discuss further the relationship between MSC and SDL. Corriveau [27] and McGregor and Korson [66] define object oriented development processes based on traceability. They highlight the importance of traceability relationships ....

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ITU (1993). Message Sequence Charts (MSC'93). Recommendation Z.120. Geneva.

....as possible, i.e. when all its predecessors in the causal order are terminated. bMSCs can be composed using a higher level formalism, called High level Message Sequence Charts(HMSCs) This notation comports se quence, loop, alternative, and parallel composition operators, that are defined in [9]. Within this paper, we will only deal with a subset of HMSCs, including sequence, alternative, and loops. So, a HMSC can be seen as a kind of bMSC automaton , and defined formally as a graph Ht : N, l, A It , where: N is a set of nodes, is a set of edges, l is a node labeling function, ....

ITU, Norm Z.120, Message Sequence Charts.

....are modeled. Among other models as e.g. a data dictionary, this activity uses a requirements object model, an object model in its conventional form with diagrams showing objects and their relations, and a use case model that consists of a set of use cases described by structured text and or MSCs [9]. System Analysis In order to achieve the required functionality, this activity identifies the architecture of the system and the most important objects to be represented in the system. The main models used in this phase are an analysis object model to describe the architecture and represent the ....

ITU-T. Recommendation Z. 120. Message sequence chart (MSC). In Criteria for the use and applicability of formal description techniques, September 1994.

....and proposes a solution for the switching of the signalling and data connections. VC switching re routing is accomplished through the Application Programming Interfaces (API) that mo dern switches offer (or their support for GSMP [20] In section 5 we present the Message Sequence Charts (MSCs [16]) for the cases of Registration and Forward Handover. We conclude this paper in section 6. 2. Network architecture The main components of the wireless architecture are Mobile Terminals (MT) Base Stations (BS) and a Control Switching Unit (CSU) MTs roam in the coverage area of BSs exchanging ....

ITU-T Recommendation Z.120, Message Sequence Chart (MSC), 1993.

....distributed systems and communications between the components of this system. The purpose of this section is to provide the reader with the features and vocabulary we will use in the rest of the article rather than providing a complete description of MSCs (which can be found in the ITU norm Z. 120 [7]) 2.1 bMSCs A bMSC ( standing for basic MSC ) denes a simple scenario, ie an abstraction of a system behaviour. Within bMSCs, processes are called instances, and are represented by a vertical axis, along which events are put in a top down order. Message exchanges are represented by arrows ....

ITU-T Message Sequence Chart (MSC) ITU-T Recommendation Z120, October 1996.

....general adoption are its intuitive graphical notation and excellent tool support. The tool support typically offers capabilities to analyse, design, implement and subsequently test systems, often using combinations of interrelated notations together with SDL such as Message Sequence Charts (MSC) [2] and Tree and Tabular Combined Notation [3] One of the main perceived benefits of SDL over other notations such as the Uniform Modelling Language [4] UML) is the ability to model and reason about, e.g. via model checking tools, detailed behavioural specifications, including real time ....

ITU-T, Rec. Z.120, Message Sequence Charts (MSC), MSC

....possible interaction between the work ows by sending and receiving messages; a scenario abstracts from internal behavior of each work ow. A set of scenarios speci es all legal interactions. Syntactically, a possibly in nite set of scenarios can be represented by high level Message Sequence Charts [3] or Sequence Diagrams in UML [7] In this paper we concentrate on the semantical foundations and, therefore, we do not x a particular representation of scenarios. The paper is structured as follows: In Sect.1 we present the basic concepts and the basic idea by the help of an example. In Sect. 2 ....

....are de ned purely semantically. An automatic checker for these conditions is subject to future research. Here, we can only present a rst idea. First of all, an automatic checker requires a syntactical representation of speci cations, e.g. in terms of high level Message Sequence Charts [3]. Given a speci cation, a checker can proceed in two steps for checking the local conditions for an agent i: 1. Reducing the set of scenarios to the ones which are relevant for agent i. For example, for checking soundness of agent Customer for the speci cation of Fig. 1, it is sucient to consider ....

ITU-T Recommendation Z.120. Message sequence charts (MSC). ITU, 1996.

....the graphic representation: Here, any two nodes n and n within the same process that have the same predecessor node n, such that n # n and n # n , are in conflict to each other, n # n . With respect to their graphic representation, EMFG s are closely related to message sequence charts (MSC) [ITU96]. The formal definition of EMFG s is closely related to that of flow event structures introduced in [Bou89] Flow event structures are a generalization of prime event structures [Nie81] where the conflict between two events is not handed down to their successors, and the partial order relation of ....

Message Sequence Chart (MSC), ITU-T Recommendation Z.120, 1996.

....and observed outcomes differ, then a fault has been discovered. However, practise has demonstrated [3, 10] that users gain further benefits (e.g. improved validation) when using graphical languages during test specification and execution. In this case, the Message Sequence Chart (MSC) language [22] appeared to be a particularly attractive candidate as a graphical means for visualising test specifications and test traces. Where, MSC is comparable to UML Sequence Diagrams (SDs) 15, 21] but in addition to the pure graphical representation provided by SDs, MSC also has a textual ....

....Message Sequence Chart (MSC) language is a graphical means for describing the behaviour of distributed reactive systems in form of traces. Syntax and semantics of MSC are defined by the International Telecommunications Union Telecommunications Standards Sector (ITU T) in Recommendation Z. 120 [22]. The MSC language comprises two sorts of diagrams: MSC diagrams and High Level MSC (HMSC) diagrams. MSCs 2 describe the interaction of entities of a distributed system (Figure 3) The entities are called instances and are represented by vertical lines with an instance head to which an instance ....

ITU-T SG 10. Message Sequence Chart (MSC) . Rec. Z.120, Geneva 1999.

....more completely, in a way that, e.g. allows test sequences to be generated without involving other information about the system (e.g. in the form of an SDL model) MSCs must then be able to express many aspects of a system that can be represented in, e.g. an SDL model. The new standard MSC 2000 [11], developed by ITU T, extends the earlier standard Supported in part by Telelogic AB, and by NUTEK through the ASTEC Competence Center. This work was carried out while Gerardo Padilla was at Telelogic AB, Uppsala MSC 96 [10] by constructs for data and high level control, so that this may be ....

....participating instances are synchronized. A B m loop[0. inf] msc Loop Fig. 1. An MSC with a Loop Inline Expression. Our semantics naturally implies a certain amount of interpretation of the ITU T standard. For instance, we use the weak form of sequential composition (in the terminology of [11]) This means, e.g. that the MSC shown in Figure 1 allows executions in which many messages can be sent by A before any of them are received by B. Our interpretation is that the standard adopts this view. However, the semantics we propose in this paper can rather easily be adapted to a stronger ....

ITU-T. Recommendation Z.120, Message Sequence Charts. Geneva, Nov. 1999.

....can be represented in, e.g. an SDL model. The new standard MSC 2000 [11] developed by ITU T, extends the earlier standard Supported in part by Telelogic AB, and by NUTEK through the ASTEC Competence Center. This work was carried out while Gerardo Padilla was at Telelogic AB, Uppsala MSC 96 [10] by constructs for data and high level control, so that this may be possible. In many approaches to test generation from MSCs (e.g. 7, 18] an MSC test purpose is viewed as specifying a set of acceptable sequences of events of the implementation. In the approaches of Autolink, TestComposer, or ....

ITU-T. Recommendation Z.120, Message Sequence Chart. Geneva, April 1996.

....This article describes the translation from Message Sequence Charts (a graphical language defining the behaviour of distributed systems) to Behaviour Description Language, a declarative object oriented reactive synchronous language. 1 Introduction Message Sequence Charts (MSCs for short) [3] is a graphical language defining the behaviour of distributed systems from scenarios. MSCs comport different hierarchical level. The lowest level, called Basic Message Sequence Charts (bMSCs) describe a causality relation between events performed by processes. On a process, events are ordered ....

ITU-T, Message Sequence Chart (MSC) ITU-T Recommendation Z120, October 1996.

....the extended classes one extends the proof for MSGs while the other extends the proof for regular MSC languages. 1 Introduction Message sequence charts (MSCs) is an ITU standardized notation widely used to capture system requirements in the early stages of design of communication protocols [ITU97,RGG96]. The clear graphical layout of an MSC describes how the components of a distributed system communicate by exchanging messages. In its simplest form, an MSC depicts the exchange of messages between processes of a distributed system and corresponds to a single partially ordered execution of the ....

ITU-TS Recommendation Z.120. Message sequence chart (MSC). ITU-TS, 1997.

....ObjectGEODE provides editors for StateChart [11] and for the SDL [13] graphical speci cation language. SDL designs can be (interactively) simulated and analyzed by an explicit state model checker. Requirements can be formalized in expressed as assertions or as Message Sequence Charts (MSC) [14]. Execution IDLE WFC RESP WFA2 WFSO RESP WFSOA WFCC WFA1 DISCONNECTED (5,6) 5,6) DATA STANDBY (1) 1) 2) 2) 7) 7) 7) 8) 8) 8) 7) 3,4) 3,4) 5,6) 1) 2) 1) Connection setup (Initializer side) 2) Connection setup (Non initializer side) 3) Data or ....

ITU-T. Message Sequence Chart (MSC), October 1996. ITU-T Recommendation Z.120.

....here on the particularly relevant aspect of inter workings between system components, i.e. on describing the typical communication scenarios required to hold, such as between the train system and the rail road crossing. Basing this on the well known and established communication standard of MSCs [24] provides at the same time a natural entry domain for the telecommunication related design aspects of FFB. The recognition of sequence charts as a natural way to elaborate on communication patterns between objects in realizing different use cases has caused their introduction into the UML standard ....

....formalism called Symbolic Timing Diagrams (STDs [16, 17] in the near future Live Sequence Charts (LSCs [13] will be supported as well. STDs are an extension of regular timing diagrams known from hardware design (cf. Section 2. 2) while LSCs are an extension of Message Sequence Charts (MSCs [24]) The generation of temporal logic formulae passes through an intermediate automata format. Again, this intermediate format allows to use several specification formalisms and is therefore the place through which LSCs are incorporated into the tool set. 126 DAMM AND KLOSE When verification ....

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ITU-T, ITU-T Recommendation Z.120: Message Sequence Chart (MSC). ITU-T, Geneva, October 1996.

....[2] Another task that is often done using MSCs is providing feature transparence , namely upgrading a communication system in a way that all the previous services are guaranteed to be supported. In recent years MSCs have gained popularity and interest. An international committee (ITU Z 120 [7]) has been working on developping standards for MSCs. Some tools for displaying MSCs and performing simple checks were developed [1, 8] We model systems of MSCs, allowing a (possibly infinite) family of (finite or infinite) executions. Each execution consists of a finite or infinite set of send ....

....0 ) j e 2 E 1 ; e 0 2 E 2 ; L(e) L(e 0 )g. Here, E 1 Delta [ E 2 means the disjoint union of the event sets of M 1 and M 2 . The concatenation of an infinite sequence M 1 ; M 2 ; is defined in an analogous way. Message sequence graphs (MSC graphs, sometimes called high level MSCs [7]) are used to compose MSCs to larger systems. Equivalently, one can compose MSCs using rational operations, i.e. union, concatenation and iteration. MSC graphs are finite directed graphs where each node of the graph is associated with a finite MSC [1] Definition 3 (MSC graph) An MSC graph N is ....

ITU-T Recommendation Z.120, Message Sequence Chart (MSC), March 1993.

.... and test purpose descriptions with the 1996 version of Message Sequence Charts (MSC 96) as input and produce test suites based on the second edition of the Tree and Tabular Combined Notation (TTCN 2) 14] Meanwhile, the standards of both SDL and MSC have been updated (SDL2000 [16] MSC 2000 [15]) and a thoroughly new version of TTCN has been standardized (TTCN 3 [7] In addition, the European Commission has set up the Interval project [21] to prototype an SDL, MSC and TTCN based tool chain for the development and testing of systems with real time constraints. During the first project ....

....Timer events are identified by a mandatory timer name and an optional timer instance name. The specification of a timer duration is optional; if it is specified, it has no semantics. Pairs of timer set and reset timeout events must be specified on the same MSC instance. 3. 2 MSC 2000 MSC 2000 [15] supports the same basic timer events as MSC 96, with some changes and refinements. First of all, the set event has been renamed to starttimer and reset is now called stoptimer. If a duration is specified, then it must be done in the form of an interval with an optional lower bound (default ....

ITU-T, Geneva, Switzerland. Message Sequence Charts, November 1999. ITU-T Recommendation Z.120.

....timer start operation immediately followed by a timeout event into the test sequence. 3 Timer in Formal Languages The formal languages MSC, SDL and TTCN all contain timer support. In this Section, an overview of the timer concepts of these languages in given. 3. 1 MSC 96 Timer support in MSC 96 [13] is very basic: there exist events to set and reset a timer, and a timeout event. Timer events are identified by a mandatory timer name and an optional timer instance name. The specification of a timer duration is optional; if it is specified, it has no semantics. Pairs of timer set and ....

ITU-T, Geneva, Switzerland. Message Sequence Charts, 1996. ITU-T Recommendation Z.120.

....language construct which obviously is still missing in the MSC standard. These new concepts allow a system modelling based on stepwise refinement starting with HyperMSCs, decomposed instances and MSC connector communication 1. Motivation The ITU standard language Message Sequence Chart (MSC) [16][17] is generally accepted as a central visual modelling technique for the description of the dynamic behaviour of systems, in particular of the communication behaviour. As such, MSC is equally popular in the telecommunication area where it is used dominantly in combination with SDL [2] as in the ....

ITU-T Rec. Z.120 (MSC-96): Message Sequence Chart (MSC). (E. Rudolph, editor), Geneva, 1996.

....objects. Automated support for constructing state machines from scenarios provides considerable help for the designer, allowing her to concentrate on sequence diagrams rather than on statechart machines. Automatic generation of statechart machines from variations of Message Sequence Charts (MSCs) [3] (including UML sequence diagrams) is implemented in several tools [4, 5, 10, 11, 12] The synthesis algorithms generalize information given in MSCs, i.e. the resulting statechart machine accepts more paths through the modeled system than represented as MSCs. The generalization is usually the ....

ITU-T Recommendation Z.120: Message Sequence Chart (MSC), ITU-T, Geneva, 1996.

....Recently, they have been also used in the development of object oriented systems, e.g. in UML. In the recent years, we observe the development of a growing number of tools and algorithms for the manipulation of MSC based designs [1 3, 7, 11, 12] The standard visual and textual notation [9] by ITU allows representing a single execution scenario, as well as a collection of scenarios, including choices and repetition. This is achieved by a notation called HMSC (High Level Message Sequence Chart) which consists of a graph, where each node contains a single MSC. The system behavior can ....

....between e and f on some process line. That is, e immediately precedes f . The transitive closure of the relation is a partial order called the visual ordering of events and it is obtained from the syntactical representation of the chart (e.g. represented according to the standard syntax ITU Z120 [9]) Clearly, the visual ordering can be defined equivalently as the transitive closure of the relation Gamma . A linearization of an MSC M = hV; P ; N ; L; T ; N;mi is a total order on V , which extends the relation (V; Example 1. Let us denote in the example MSC given in Figure 1 by e i ....

ITU-T Recommendation Z.120, Message Sequence Chart (MSC), 1996.

....results are stronger and imply that, over an appropriate universe, satis ability and synthesis of MSCs and MSGs, respectively, are decidable. 1 Introduction Message sequence charts (MSC) are a popular visual formalism used to describe design requirements of concurrent message passing systems [16, 10]. They are used to describe behaviours of systems in early models of system design. An MSC describes a single partially ordered execution of the system and a collection of these diagrams formalize the set of possible scenarios exhibited by a model. These diagrams are usually used in the design of ....

ITU-TS Recommendation Z.120. Message sequence chart (MSC). ITU-TS, 1997.

....to the telecommunications domain, and it provides a concise comparison in terms of the criteria seen in Section 2.2. Message Sequence Charts (MSCs) The scenario notation that is the most commonly used by telecommunications companies and standards bodies is undoubtedly Message Sequence Charts [45]. This notation describes exchanges of messages (arrows) between communicating entities (vertical lines) MSCs are essentially graphical (although a textual machine processable format exists) composed of concrete events (messages) and centered towards components. MSCs can represent internal ....

ITU-T (2000) Recommendation Z. 120: Message Sequence Chart (MSC). Geneva.

....and standards is generally composed of three major stages. At Stage 1, services are described from the user s point of view in prose form and with use cases. The focus of the second stage is on control flows between the different entities involved, represented using Message Sequence Charts (MSCs) [19]. 2 To appear in SDL 01, c # Springer Verlag, 2001 Finally, Stage 3 aims to provide (informal) specifications of protocols and procedures. Formal specifications are sometimes provided (e.g. in SDL [18] but overall they still su#er from a low penetration, especially in North America. In such ....

ITU-T: Recommendation Z.120, Message Sequence Chart (MSC). Geneva (1999)

....is undecidable. 1 Introduction Message Sequence Charts (MSCs) are a commonly used visual notation for describing message exchanges between concurrent processes. They have become popular among software engineers for early requirements specification. Recently MSCs have been standardized by ITU [12], and incorporated in modern software engineering notations such as UML [5] In the simplest form, an MSC depicts the desired exchange of messages, and corresponds to a single (partial order) execution of the system. In recent years, a variety of features have been introduced so that a designer ....

ITU-T recommendation Z.120. Message Sequence Charts (MSC'96), 1996.

....objects (instances) and horizontal directed lines are messages. Time ows from the top to down in the chart; for example Message1 is sent before Message2 and so on. The time axis shows only sequence; neither the scale is linear nor a scale provided. For details on MSC, readers are referred to [7, 6, 11, 5, 8]) Each message in Figure 1 has an optional identi er to the left or right of it; in this case, a letter from a to j . Additionally, they can be included in timing mark expressions to indicate relative time between events. The standards of MSCs de ned by ITU, de nes the Table 1. Textual Syntax ....

....delivery. The label [2, 3] on the vertical line of Instance2 from b to d speci es bounds on the delay between b and d , and models an assumption about the speed of process Instance2 . Intervals may be open, closed or half closed and may be extend to in nity on the right (e.g. 0, 1) [2, 5], 3, 7] where the round brace indicates an open interval, and the square brace a closed one) As far as constraints on the message delivery and processor s speed are concerned, a delay interval is delimited with respect to the occurrence of two consecutive visually ordered events. 2.2 ....

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ITU-TS. Recommendation Z.120 : Message Sequence Chart. Geneva, 1996.

....to the conference bridge module. It seemed to us that it would be wiser to show the sequence computed for this module, as far as it allows a better understanding of a conference bridge the sequence for the components being less clear. We got a sequence of length 247, expressed in the MSC [10] format and in the TTCN [8] notation. Figure 4 is the simplified MSC for the test sequence obtained for the module representing the bridge conference terminal. This sequence brings to light all the interactions of this module (it indeed covers all the transitions) We only show here the signal ....

ITU-T, Geneva. Recommendation Z. 120 Message Sequence Charts, (MSC), 1996.

....during migration, through any available terminals or computers owned by the user or provided by the service provider or a third party on location. To achieve our goals several new techniques are employed and integrated into our system. We selected SDL (Specification and Description Language) of ITU (ITU Z.100, 1992) and the related methodology to reinforce the design and development process with formalism. Our design of UPC relies on the following emerging techniques technologies: The Internet Engineering Task Force approved in October 1996 the IP Mobility Support (MIP) protocol (RFC 2002, 1996) which ....

....requirements. This work essentially differs from the previous one, since it is not based on an existing standard or specification. For the design of the UPC system we apply Verilog s SDL tool: ObjectGEODE (ObjectGEODE, 1997) Beside SDL, ObjectGEODE supports MSC (Message Sequence Chart) of ITU (ITU Z.120, 1992), OMT of (Derr, K.W. 1995) and state and entity relationship diagrams to help the design and documentation process. It provides tools for the entire system life cycle. We present this work in the following sections of the paper. Before going to the details of our results we give a short summary ....

ITU Z.120 (1992) Message Sequence Chart (MSC).

....stage conforms to the product of the previous stage. For instance, at the end of the design phase, the design speci cation should be validated against the requirement speci cation. Various formal techniques have been introduced into the software development cycles. Message Sequence Charts (MSC) [9] is a speci cation language used to describe the communication between components in a distributed system. MSC has been standardized by the ITU TS [9] Generally, it is used at the rst stage to describe the requirements of a system under consideration. These requirements can represent di erent ....

....the requirement speci cation. Various formal techniques have been introduced into the software development cycles. Message Sequence Charts (MSC) 9] is a speci cation language used to describe the communication between components in a distributed system. MSC has been standardized by the ITU TS [9]. Generally, it is used at the rst stage to describe the requirements of a system under consideration. These requirements can represent di erent views in an abstract manner. In the design stage, designers will develop a solution to these requirements and refer to as a design speci cation. At this ....

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ITU-T. Recommendation Z.120: Message Sequence Charts. ITU-T, Genve, Octobre 1996. Rvise.

....speci cations into propositional logic. The solver SATO [31] based on the Davis Putnam approach to satis ability in propositional logic, is then used for determining test sequences. These sequences can be displayed graphically as a time synchronous variant of Message Sequence Charts (MSCs [14]) This approach to determining test sequences can be seen as a special application of bounded model checking. However, a set of common test case speci cations can be formulated without referring to the Linear Time Logic (LTL) which results in eciency gains, and more importantly, in a ....

....ports of connected components and the cycle is repeated. This results in a time synchronous communication scheme with bu er size 1. Interaction view: MSCs. Message Sequence Charts (MSCs) are used to describe the interaction of components. In contrast to Message Sequence Charts as de ned 3 in [14], AutoFocus MSCs refer to time synchronous systems. In the following, the term MSC always denotes these time synchronous sequence charts. Progress of time is explicitly modeled by ticks which are represented by dashed lines. All actions between two successive ticks are considered to occur ....

ITU. ITU-T Recommendation Z.120: Message Sequence Charts (MSC), November 1999.

....20. It is the TTCN 3 representation of the TTCN test case in Figure 13. In addition to the pure textual format, TTCN 3 will define at least two presentation formats: A tabular conformance testing presentation format [5] that resembles the tabular form of TTCN and a graphical presentation format [6, 8] that supports the presentation and also the development of TTCN 3 test cases, as Message Sequence Charts (MSC) ....

ITU. Message Sequence Chart (MSC). Geneva, 2000. (ITU-T Recommendation Z.120.)

....of the component modules. Simulation is the validation technique used in this methodology. We note that if simulation is used as a mechanism for validation then the results of the simulation must be compared against an a priori description of the system s behaviour. A Message Sequence Chart (MSC) [ITU T 1993] is a special type of event trace used to depict the results of the simulation of an SDL design. Generally, the detailed nature of the MSCs make them practically unusable as a means of validating the behaviour of the system from the viewpoint of the analyst or customer (user) both of whom have ....

ITU-T, Z.120, Message Sequence Chart (MSC), 1993.

....as the example language for which we develop a syntax definition. MSC is a graphical language for the description of interaction between entities. A diagram in MSC describes which messages are interchanged between process instances, and what internal actions they perform. MSC has been standardized [5, 10], but this definition mainly deals with a textual version of MSC. Here, we will define the visual syntax of MSC, and consider the textual representation as the meaning which can be obtained as interpretation of the abstract syntax graph. Fig. 3 shows a (very simple) diagram in MSC, consisting of ....

ITU-T, Geneva. Recommendation Z.120: Message Sequence Chart (MSC), 1993. See also: http://www.win.tue.nl/win/cs/fm/sjouke/msc.html.

....to explore the critical concepts of security in a controlled and expressive environment without having to actually do an implementation or make use of multiple tools to analyse different facets of a protocol. 3 Selection of Formalism We based our formalism on MSC type (Message Sequence Chart) [13] semantics as it is ideally suited to our purposes. MSC s capture the exchange of protocol messages at a higher level than, for example SDL [6, 2, 8] which we believe is more appropriate to cryptographic protocol design, where a lot of effort (and support) is required for message content ....

ITU. ITU-TS Recommendation Z.120: Message Sequence Chart (MSC). ITU-TS, Geneva, 1996.

....and begin y1: x; y2: 1; while y1 =100 or y2= 1 do begin if y1 =100 then begin y1: y1 11; y2: y2 1 end else begin y1: y1 10; y2: y2 1 end end; z: y1 10 end. Figure 1: Floyd s 101 program refining it into a full system. Using standard notation, such as message sequence charts [3], conforms with the usual start of the design. On the other hand, automatic code generation is still add hoc, and it is not expected that the code generated would be efficient or elegant (although it is, by definition, well documented) Our approach for testing is quite the complement to the ....

ITU-T Recommendation Z.120, Message Sequence Chart (MSC), March 1993.

....(Scenarios) Stage 3: Protocol Procedure Specifications Protocols Procedures Requirements Stage 1 MSCs Stage 2 Stage 3 Fig. 1. Three stage methodology stage is on control flows between the di#erent entities involved, represented using sequence diagrams or Message Sequence Charts (MSCs [22]) Finally, stage 3 aims to provide (informal) specifications of protocols and procedures. Formal specifications are sometimes provided (e.g. in SDL [21] but overall they still su#er from a low penetration [10,17] especially in North America [2,18] ITU T developed this three stage methodology ....

ITU-T: Recommendation Z.120, Message Sequence Chart (MSC). Geneva, Switzerland, 2000.

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ITU: Recommendation Z. 120: Message Sequence Chart (MSC). ITU, Geneva, 1996.

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Itu telecommunication standardisation sector, itu-t reccomendation z.120. message sequence charts. (msc'96). Geneva 1996.

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ITU. ITU-TS Recommendation Z.120: Message Sequence Chart (MSC). ITU-TS, Geneva, 1996.

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ITU Z.120 (1996). Message Sequence Chart (MSC). Technical report, Telecommunication Standardization Sector of International Telecommunication Union, Geneva, Switzerland. Z.120.

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ITU. ITU-TS Recommendation Z.120: Message Sequence Chart (MSC). ITU-TS, Geneva, 1996.

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ITU. ITU-TS Recommendation Z.120: Message Sequence Chart (MSC). ITU-TS, Geneva, 1996.

No context found.

ITU: Recommendation Z. 120: Message Sequence Chart (MSC). ITU, Geneva, 1996.

No context found.

ITU-T Recommendation Z.120: Message Sequence Chart (MSC), ITU-T, Geneva, 1996.

No context found.

ITU, Norm Z.120, Message Sequence Charts. 15

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