ITU Workshop Use of Description Techniques Geneva 23

ITU Workshop "Use of Description Techniques" Geneva, 23. Nov. 2002 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 on "Use of Description Techniques"

“Use of OOM and UML to define Signalling Requirements” A little story about a personal experience in. . . attempting to motivate the use of object-oriented modelling techniques in SG 11. . . advocating the advantages for the experts’ work. . . the attention achieved in the process. . . observations and conclusions ITU Workshop on "Use of Description Techniques" 03/12/2020 2

“Use of OOM and UML to define Signalling Requirements” Contents 1 Introduction – Preamble – About Signalling Requirements – The OOM Story in SG 11 2 Why OO-Modelling & UML – OO-Analysis & -Design (OOA/D) – OO-Modelling (OOM) – Telecom vs. Computing Intro OOM 3 OOM for BICC Requirements – Purpose and Benefits – Existing BICC CS 2 Signalling Requirements – Supplementing BICC Signalling Requirements 4 Results & Conclusion – Reception by the meetings – Personal observations – Long-term view BICC Results ITU Workshop on "Use of Description Techniques" 03/12/2020 3

“Use of OOM and UML to define Signalling Requirements” 1 Introduction – Preamble – About Signalling Requirements – The OOM Story in SG 11 2 Why OO-Modelling & UML – OO-Analysis & -Design (OOA/D) – OO-Modelling (OOM) – Telecom vs. Computing Intro OOM 3 OOM for BICC Requirements – Purpose and Benefits – Existing BICC CS 2 Signalling Requirements – Supplementing BICC Signalling Requirements 4 Results & Conclusion – Reception by the meetings – Personal observations – Long-term view BICC Results ITU Workshop on "Use of Description Techniques" 03/12/2020 4

“Use of OOM and UML to define Signalling Requirements” SG 11 Signalling Requirements - what’s 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 Intro OOM BICC Results – Signalling [network] architecture and functional elements – Description of network functions that are needed – Functional elements to be implemented ( != physical elements) Ideally. . . ITU Workshop on "Use of Description Techniques" 03/12/2020 5

“Use of OOM and UML to define Signalling Requirements” The Proposal for SG 11 BICC Capability Set 3 (Bearer Independent Call Control) Intro – BICC is a framework for providing ISDN services over transport technologies beyond simply TDM: ATM AAL 1, AAL 2, IP, MPLS. – In the light of the starting BICC CS 3 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 SG 11 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 OOM BICC Results ITU Workshop on "Use of Description Techniques" 03/12/2020 6

“Use of OOM and UML to define Signalling Requirements” 1 Introduction – Preamble – Story line – About myself and SG 11 2 Why OO-Modelling & UML – OO-Analysis & -Design (OOA/D) – OO-Modelling (OOM) – Telecom vs. Computing Intro OOM 3 OOM for BICC Requirements – Purpose and Benefits – Existing BICC CS 2 Signalling Requirements – Supplementing BICC Signalling Requirements 4 Results & Conclusion – Reception by the meetings – Personal observations – Long-term view BICC Results ITU Workshop on "Use of Description Techniques" 03/12/2020 7

“Use of OOM and UML to define Signalling Requirements” Object-Oriented Analysis & Design (OOA/D) § A very, very little history: – late 1980 s: OO programming languages (Smalltalk, C++) – early 1990 s: OOA/D techniques (Booch, Rumbaugh, Jacobson, . . . ) – late 1990 s: 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 user’s perspective – OOD: Intro OOM BICC Results 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. ITU Workshop on "Use of Description Techniques" 03/12/2020 8

“Use of OOM and UML to define Signalling Requirements” 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. : Intro OOM BICC Results – 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? ITU Workshop on "Use of Description Techniques" 03/12/2020 9

“Use of OOM and UML to define Signalling Requirements” Telecommunication vs. Computing § Telecommunication & computing industry is converging – How will the demarcation line look like in - let’s 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 won’t remain stand-alone products – As a consequence, the dominant customers of ITU standards will more and more be. . . Intro OOM BICC Results – software engineers for whom OOM has become everyday practise – service providers which need to cope with the increased complexity ITU Workshop on "Use of Description Techniques" 03/12/2020 § Telecom services convergence, a long-term business need 10

“Use of OOM and UML to define Signalling Requirements” 1 Introduction – Preamble – Story line – About myself and SG 11 2 Why OO-Modelling & UML – OO-Analysis & -Design (OOA/D) – OO-Modelling (OOM) – Telecom vs. Computing Intro OOM 3 OOM for BICC Requirements – Purpose and Benefits – Existing BICC CS 2 Signalling Requirements – Supplementing BICC Signalling Requirements 4 Results & Conclusion – Reception by the meetings – Personal observations – Long-term view BICC Results ITU Workshop on "Use of Description Techniques" 03/12/2020 11

“Use of OOM and UML to define Signalling Requirements” OOM @ BICC: Purpose and Benefits OOM can be used to: Benefits: § define processes and information flows § further refine the scope of BICC capabilities and their protocols § identify relationships between processes and information § improve the common understanding of terminology § increase the degree of reuse (protocol) requirements and components § improved documentation of BICC and its evolution (CS 1. . CS 3) § improve quality control and consistency check on protocol designs Intro OOM BICC Results ITU Workshop on "Use of Description Techniques" 03/12/2020 § trace protocol standardisation (from req’s to test specifications) 12

“Use of OOM and UML to define Signalling Requirements” Existing BICC CS 2 Signalling Requirements Signalling Transport Network TE Other service supplier networks Call Control Signalling Bearer Control Signalling Call & Bear Control (CBC) Signalling TE Access Control Signalling Access Network TSN-x ISN-A CSF-N TE BCF-N (v) Bearer Inter-working Function (BIWF) GSN-x CSF-T SWN-1 BCF-R BCF-T (w) Backbone Network Connection Link Intro CSF-G SWN-2 BCF-R BCF-G (x) CMN-x GSN-y CSF-C CSF-G BCF-G (y) BCF-J SWN-3 BCF-R ISN-B ACNE CSF-R CSF-N BCF-N (z) ACN-w BCF-R BCF-A (a) TE Joint Domain Bearer Inter-working Function (BIWF) Backbone Network Connections Network Bearer Connection (end to end) OOM Scope of Signalling Requirements BICC Results ITU Workshop on "Use of Description Techniques" 03/12/2020 13

“Use of OOM and UML to define Signalling Requirements” Supplementing BICC Signalling Requirements Overall 1/6 Requirements Intro OOM Use Cases -> helps to refine scope BICC Results ITU Workshop on "Use of Description Techniques" 03/12/2020 14

“Use of OOM and UML to define Signalling Requirements” Supplementing BICC Signalling Requirements 2/6 Flows Information Intro OOM Use Case -> overview of scenarios BICC Results ITU Workshop on "Use of Description Techniques" 03/12/2020 15

“Use of OOM and UML to define Signalling Requirements” Supplementing BICC Signalling Requirements 3/6 Model Information Intro OOM Class diagrams -> improve understanding the principle idea of BICC Results ITU Workshop on "Use of Description Techniques" 03/12/2020 16

“Use of OOM and UML to define Signalling Requirements” Supplementing BICC Signalling Requirements 4/6 Information Model further refined class Intro diagrams OOM BICC Results ITU Workshop on "Use of Description Techniques" 03/12/2020 17

“Use of OOM and UML to define Signalling Requirements” Supplementing BICC Signalling Requirements 5/6 Zooming into individual BICC components “Play it again Sam!”, and: Intro OOM BICC Results ITU Workshop on "Use of Description Techniques" 03/12/2020 18

“Use of OOM and UML to define Signalling Requirements” Supplementing BICC Signalling Requirements 5/6 be much more to be modelled! And there’d Intro OOM BICC Results ITU Workshop on "Use of Description Techniques" 03/12/2020 19

“Use of OOM and UML to define Signalling Requirements” 1 Introduction – Preamble – Story line – About myself and SG 11 2 Why OO-Modelling & UML – OO-Analysis & -Design (OOA/D) – OO-Modelling (OOM) – Telecom vs. Computing Intro OOM 3 OOM for BICC Requirements – Purpose and Benefits – Existing BICC CS 2 Signalling Requirements – Supplementing BICC Signalling Requirements 4 Results & Conclusion – Reception by the meetings – Personal observations – Long-term view BICC Results ITU Workshop on "Use of Description Techniques" 03/12/2020 20

“Use of OOM and UML to define Signalling Requirements” Reception by the Meeting (of WP 2/11) Achieved Interest § Remarkable interest shown by SG 11 management § Moderate interest seen from participants progressing work § Gap between S. P. and Suppliers Statement of Scepticism § Nice, but do we really need this? Intro OOM BICC Results § Learning curve steep enough? § Return on investment? ITU Workshop on "Use of Description Techniques" 03/12/2020 Possible Reasons for Spectisism (Past) Experiences with Notations § SDL: Widely adopted within SG 11 (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” 21

“Use of OOM and UML to define Signalling Requirements” Personal Observations “Contemporary” factors “Hidden” factors § Time pressure § Conceptual work -> get out standards fast § Little resources available -> reduce efforts to the minimum § Increased Fluctuation -> people change, know-how changes. . . § Current quality control system Intro OOM -> iterative approach: changes to standards as implementers discover imperfect parts BICC Results ITU Workshop on "Use of Description Techniques" 03/12/2020 – 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 22

“Use of OOM and UML to define Signalling Requirements” Personal Long-term Views Think positive! Summing up § Complexity in telecom will continue to increase § Need for conceptual work -> a common understanding of technical and conceptual issues is indispensable § Parties with particular interest in transparency: Intro OOM BICC Results – Governments: regulation, lawful interception – Service Providers: service convergence challenge, cope with network complexity ITU Workshop on "Use of Description Techniques" 03/12/2020 – 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 23

“Use of OOM and UML to define Signalling Requirements” Thank you!. . . and enjoy your stay in Switzerland . . . despite the *? +!%ç&*/ weather! coffee break now? psst! ITU Workshop on "Use of Description Techniques" 03/12/2020 24

“Use of OOM and UML to define Signalling Requirements” Supplemental BACKUP ITU Workshop on "Use of Description Techniques" 03/12/2020 25

“Use of OOM and UML to define Signalling Requirements” Links & Book References 1/2 OOA/D § http: //www. sdmagazine. com/articles/1999/0006 a/0006 a. htm § “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 Intro OOM § http: //www. ambysoft. com/e. Commerce. Architecture. html § http: //www. sdmagazine. com/articles/1999/0004 o/0004 o. htm § “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) BICC Results ITU Workshop on "Use of Description Techniques" 03/12/2020 26

“Use of OOM and UML to define Signalling Requirements” Links & Book References 2/2 UML § http: //www. omg. org/uml § http: //www. rational. com/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 ITU Workshop on "Use of Description Techniques" 03/12/2020 27