The Use of OO-Modelling Principles (OOM) and UML Notation to Define Signalling Requirements Raphael J. Schumacher, Rapporteur Q.8/11 Swisscom AG, Switzerland ITU Workshop "Use of Description Techniques" Geneva, 23. Nov. 2002

Use of OOM and UML to define Signalling Requirements 2 ITU Workshop on "Use of Description Techniques" Geneva, 23 November 2002 A little story about a personal experience in... attempting to motivate the use of object-oriented modelling techniques in SG11... advocating the advantages for the experts work... the attention achieved in the process... observations and conclusions

Use of OOM and UML to define Signalling Requirements 3 ITU Workshop on "Use of Description Techniques" Geneva, 23 November 2002 Contents 1Introduction –Preamble –About Signalling Requirements –The OOM Story in SG11 2Why OO-Modelling & UML –OO-Analysis & -Design (OOA/D) –OO-Modelling (OOM) –Telecom vs. Computing 3OOM for BICC Requirements –Purpose and Benefits –Existing BICC CS2 Signalling Requirements –Supplementing BICC Signalling Requirements 4Results & Conclusion –Reception by the meetings –Personal observations –Long-term view Intro OOM BICC Results

Use of OOM and UML to define Signalling Requirements 4 ITU Workshop on "Use of Description Techniques" Geneva, 23 November Introduction –Preamble –About Signalling Requirements –The OOM Story in SG11 2Why OO-Modelling & UML –OO-Analysis & -Design (OOA/D) –OO-Modelling (OOM) –Telecom vs. Computing 3OOM for BICC Requirements –Purpose and Benefits –Existing BICC CS2 Signalling Requirements –Supplementing BICC Signalling Requirements 4 Results & Conclusion –Reception by the meetings –Personal observations –Long-term view Intro OOM BICC Results

Use of OOM and UML to define Signalling Requirements 5 ITU Workshop on "Use of Description Techniques" Geneva, 23 November 2002 SG11 Signalling Requirements - whats this? Question to be answered before protocol development starts:What do we expect the particular signalling protocol to do? A collection of functional requirements on a signalling protocol that is destined for specific purposes and applications: –That is, signalling requirements need to identify... –The context of usage (= equal to an applicability statement?) –All the scenarios that need to be applicable –Hence signalling requirements would contain –Signalling [network] architecture and functional elements –Description of network functions that are needed –Functional elements to be implemented ( != physical elements) Ideally... Intro OOM BICC Results

Use of OOM and UML to define Signalling Requirements 6 ITU Workshop on "Use of Description Techniques" Geneva, 23 November 2002 The Proposal for SG11 BICC Capability Set 3 (Bearer Independent Call Control) –BICC is a framework for providing ISDN services over transport technologies beyond simply TDM: ATM AAL1, AAL2, IP, MPLS. –In the light of the starting BICC CS3 activity, further ways to improve the modelling techniques for envisaged signalling architecture were seeked. –This resulted in a contribution brought into WP 2/11 at the SG11 meeting in Mai 2001: Delayed Contribution D.229 – 2/11 Aim: to propagate the idea of using OOM and UML for the development of signalling requirements Intro OOM BICC Results

Use of OOM and UML to define Signalling Requirements 7 ITU Workshop on "Use of Description Techniques" Geneva, 23 November Introduction –Preamble –Story line –About myself and SG11 2Why OO-Modelling & UML –OO-Analysis & -Design (OOA/D) –OO-Modelling (OOM) –Telecom vs. Computing 3OOM for BICC Requirements –Purpose and Benefits –Existing BICC CS2 Signalling Requirements –Supplementing BICC Signalling Requirements 4 Results & Conclusion –Reception by the meetings –Personal observations –Long-term view Intro OOM BICC Results

Use of OOM and UML to define Signalling Requirements 8 ITU Workshop on "Use of Description Techniques" Geneva, 23 November 2002 Object-Oriented Analysis & Design (OOA/D) A very, very little history: –late 1980s: OO programming languages (Smalltalk, C++) –early 1990s: OOA/D techniques (Booch, Rumbaugh, Jacobson,...) –late 1990s: joint effort to develop the UML standard; adopted by OMG OOA&D as conceptual tool was originally directly associated with software development: –OOA: Analysing a system and its environment, as well as the requirements on the system, seen from a users perspective –OOD: Documentation on the concept, and the design of the implementation (== the inside of the system) –UML: UML as notation standard; UML tools with the purpose to automatically create program code out of the object-oriented models. Intro OOM BICC Results

Use of OOM and UML to define Signalling Requirements 9 ITU Workshop on "Use of Description Techniques" Geneva, 23 November 2002 Object-Oriented Modelling (OOM) Simply going beyond the purpose of developing software : –OOA, OOD & UML are description techniques, thus probably also applicable for other things than software development. –Meanwhile, modelling is used in many areas, e.g.: –Business engineering: modelling of enterprises in terms of purpose, processes and organisational entities –Service development: service components and their associations amongst themselves as well to network capabilities –Database design & data warehouses: data structures, specifications for data mining and information exchange (XML/DTD) –Telecom Operations Map (TOM): a framework for a process architecture suitable to telecommunications service providers –Network Management Systems: managed objects (MIBs) Why not make profit from OOM & UML in ITU efforts as well? Intro OOM BICC Results

Use of OOM and UML to define Signalling Requirements 10 ITU Workshop on "Use of Description Techniques" Geneva, 23 November 2002 Telecommunication vs. Computing Telecommunication & computing industry is converging –How will the demarcation line look like in - lets say - 5 years? A grey area by best... –Who will be faced to communication standards in future? –SW developers incorporating telecom modules into vertical products –Integrators struggling with service convergence telecommunication services wont remain stand-alone products –As a consequence, the dominant customers of ITU standards will more and more be... –software engineers for whom OOM has become everyday practise –service providers which need to cope with the increased complexity Telecom services convergence, a long-term business need consolidating portfolios require clean concepts, interfaces & APIs Intro OOM BICC Results

Use of OOM and UML to define Signalling Requirements 11 ITU Workshop on "Use of Description Techniques" Geneva, 23 November Introduction –Preamble –Story line –About myself and SG11 2Why OO-Modelling & UML –OO-Analysis & -Design (OOA/D) –OO-Modelling (OOM) –Telecom vs. Computing 3OOM for BICC Requirements –Purpose and Benefits –Existing BICC CS2 Signalling Requirements –Supplementing BICC Signalling Requirements 4Results & Conclusion –Reception by the meetings –Personal observations –Long-term view Intro OOM BICC Results

Use of OOM and UML to define Signalling Requirements 12 ITU Workshop on "Use of Description Techniques" Geneva, 23 November 2002 BICC: Purpose and Benefits OOM can be used to: define processes and information flows identify relationships between processes and information increase the degree of reuse (protocol) requirements and components Benefits: further refine the scope of BICC capabilities and their protocols improve the common understanding of terminology improved documentation of BICC and its evolution (CS1..CS3) improve quality control and consistency check on protocol designs trace protocol standardisation (from reqs to test specifications) Intro OOM BICC Results

Use of OOM and UML to define Signalling Requirements 13 ITU Workshop on "Use of Description Techniques" Geneva, 23 November 2002 Existing BICC CS2 Signalling Requirements Intro OOM BICC Results Scope of Signalling Requirements

Use of OOM and UML to define Signalling Requirements 14 ITU Workshop on "Use of Description Techniques" Geneva, 23 November 2002 Supplementing BICC Signalling Requirements 1/6 Overall Requirements Use Cases -> helps to refine scope Intro OOM BICC Results

Use of OOM and UML to define Signalling Requirements 15 ITU Workshop on "Use of Description Techniques" Geneva, 23 November 2002 Supplementing BICC Signalling Requirements 2/6 Information Flows Use Case -> overview of scenarios Intro OOM BICC Results

Use of OOM and UML to define Signalling Requirements 16 ITU Workshop on "Use of Description Techniques" Geneva, 23 November 2002 Supplementing BICC Signalling Requirements 3/6 Intro OOM BICC Results Information Model Class diagrams -> improve understanding the principle idea of BICC

Use of OOM and UML to define Signalling Requirements 17 ITU Workshop on "Use of Description Techniques" Geneva, 23 November 2002 Supplementing BICC Signalling Requirements 4/6 Intro OOM BICC Results Information Model further refined class diagrams

Use of OOM and UML to define Signalling Requirements 18 ITU Workshop on "Use of Description Techniques" Geneva, 23 November 2002 Supplementing BICC Signalling Requirements 5/6 Intro OOM BICC Results Zooming into individual BICC components Play it again Sam!, and:

Use of OOM and UML to define Signalling Requirements 19 ITU Workshop on "Use of Description Techniques" Geneva, 23 November 2002 Supplementing BICC Signalling Requirements 5/6 Intro OOM BICC Results And thered be much more to be modelled!

Use of OOM and UML to define Signalling Requirements 20 ITU Workshop on "Use of Description Techniques" Geneva, 23 November Introduction –Preamble –Story line –About myself and SG11 2Why OO-Modelling & UML –OO-Analysis & -Design (OOA/D) –OO-Modelling (OOM) –Telecom vs. Computing 3OOM for BICC Requirements –Purpose and Benefits –Existing BICC CS2 Signalling Requirements –Supplementing BICC Signalling Requirements 4Results & Conclusion –Reception by the meetings –Personal observations –Long-term view Intro OOM BICC Results

Use of OOM and UML to define Signalling Requirements 21 ITU Workshop on "Use of Description Techniques" Geneva, 23 November 2002 Reception by the Meeting (of WP 2/11) Achieved Interest Remarkable interest shown by SG11 management Moderate interest seen from participants progressing work Gap between S.P. and Suppliers Statement of Scepticism Nice, but do we really need this? Learning curve steep enough? Return on investment? UML not a bit too formal? Possible Reasons for Spectisism (Past) Experiences with Notations SDL: Widely adopted within SG11 (protocol standards, typically specifying the state machines), but applied in the right way? TTCN: ratio of sophistication vs. value was not perceived to be very promising to individuals Little popularity of concept work With IP, everything is easier Intro OOM BICC Results

Use of OOM and UML to define Signalling Requirements 22 ITU Workshop on "Use of Description Techniques" Geneva, 23 November 2002 Personal Observations Contemporary factors Time pressure ->get out standards fast Little resources available ->reduce efforts to the minimum Increased Fluctuation ->people change, know-how changes... Current quality control system ->iterative approach: changes to standards as implementers discover imperfect parts Hidden factors Conceptual work –generally having a hard time –benefits not convincing enough ITU hidden law: A playground for different parties with particular interests. Lobbying e.g. to... –advocate a specific solution –slow down progress of work? ->often, full transparency is not necessarily desired ->poisons top down approaches Intro OOM BICC Results

Use of OOM and UML to define Signalling Requirements 23 ITU Workshop on "Use of Description Techniques" Geneva, 23 November 2002 Personal Long-term Views Think positive! Complexity in telecom will continue to increase ->a common understanding of technical and conceptual issues is indispensable Parties with particular interest in transparency: –Governments: regulation, lawful interception –Service Providers: service convergence challenge, cope with network complexity Summing up Need for conceptual work –still an indisputable necessity –adoption of new techniques takes a lot of time -> patience with optimism Factors for success/failure: –on actual participation (parties) –market pressures (competition) –the mood of telecom business Better days will be coming again Intro OOM BICC Results

Use of OOM and UML to define Signalling Requirements 24 ITU Workshop on "Use of Description Techniques" Geneva, 23 November 2002 Thank you!...and enjoy your stay in Switzerland...despite the *?+!%ç&*/ weather! coffee break now? psst!

Use of OOM and UML to define Signalling Requirements 25 ITU Workshop on "Use of Description Techniques" Geneva, 23 November 2002 Supplemental BACKUP

Use of OOM and UML to define Signalling Requirements 26 ITU Workshop on "Use of Description Techniques" Geneva, 23 November 2002 Links & Book References1/2 OOA/D Building Object Applications That Work: Your Step-By-Step Handbook for Developing Robust Systems with Object Technology by Scott W. Ambler (Cambridge University Press, 1998) OOM Business Engineering With Object Technology by David Taylor (John Wiley and Sons, 1995) Enterprise Modelling with UML by Chris Marshall (Addison-Wesley, Object Technology series, 1999) Intro OOM BICC Results

Use of OOM and UML to define Signalling Requirements 27 ITU Workshop on "Use of Description Techniques" Geneva, 23 November 2002 Links & Book References2/2 UML The Unified Modeling Language Reference Manual by Grady Booch, James Rumbaugh, and Ivar Jacobson (Addison-Wesley, Object Technology Series, 1999) The Unified Modeling Language User Guide by Grady Booch, James Rumbaugh, and Ivar Jacobson (Addison-Wesley, Object Technology Series, 1999) Intro OOM BICC Results