1. ITU-T Languages @ SDOs Amardeo Sarma Co-Chairman, ITU-T Study Group 17

2. ITU-T Study Group 17 Goal of standardisations Create a common understanding for and define Create a common understanding for and define  Infrastructure  Products  Services  Protocols Enable Communication Enable Communication Enable interoperability and compatibility Enable interoperability and compatibility Ease the life of providers and users Ease the life of providers and users

3. ITU-T Study Group 17 Special Core Competencies at ITU-T Carrier class standards and specifications Carrier class standards and specifications Experts and drivers in Telecommunications Experts and drivers in Telecommunications Strong organisational and logistic support by the TSB Strong organisational and logistic support by the TSB Fast standards track Fast standards track  make even better standards faster Quality of standards play a key role

4. ITU-T Study Group 17 Writing standards Natural languages Natural languages Tables Tables Diagrams, e.g. sequence diagrams Diagrams, e.g. sequence diagrams State diagrams State diagrams............ Usually informal – meaning unclear

5. ITU-T Study Group 17 Improve standards clarity Natural languages and informal aids not enough Natural languages and informal aids not enough Use formalised techniques Use formalised techniques  Meaning (semantics) of used notation  Allow automatic checking  Machine-readable specifications – automatic implementation Since the 70s, ITU-T (then CCITT) has developed FDTs – formal description techniques Since the 70s, ITU-T (then CCITT) has developed FDTs – formal description techniques Today: ITU-T Language Family Today: ITU-T Language Family

6. ITU-T Study Group 17 What makes the family different? Real-time, distributed communicating systems Real-time, distributed communicating systems Formal, allowing verification and validation Formal, allowing verification and validation  Supports transparency and security requirements Many languages with a graphical syntax Many languages with a graphical syntax Commercial tool support Commercial tool support  Tool availability required for approval  Tools vendors directly involved in work Catering for users both in Industry and in Standards bodies (SDOs), e.g. ITU-T SG 11 Catering for users both in Industry and in Standards bodies (SDOs), e.g. ITU-T SG 11

7. ITU-T Study Group 17 The ITU-T language family SDL – Specification and Description Language SDL – Specification and Description Language MSC – Message Sequence Chart MSC – Message Sequence Chart eODL – extended Object Definition Language eODL – extended Object Definition Language ASN.1 – Abstract Syntax Notation One ASN.1 – Abstract Syntax Notation One TTCN – Tree and Tabular Combined Notation TTCN – Tree and Tabular Combined Notation CHILL – CCITT HIgh-Level Language CHILL – CCITT HIgh-Level Language URN – User Requirements Notation URN – User Requirements Notation Incorporating Time and Performance into the languages Incorporating Time and Performance into the languages

8. ITU-T Study Group 17 Language Usage Initially, languages were mainly aimed at standards and Recommendations Initially, languages were mainly aimed at standards and Recommendations For the core languages, industrial use has today far outgrown use in standards! For the core languages, industrial use has today far outgrown use in standards! There is considerable potential left for SDOs to: There is considerable potential left for SDOs to:  Improve quality of standards  Reduce time for standards development But: Use requires some investment But: Use requires some investment

9. ITU-T Study Group 17 Our Strategy at ITU-T SG 17 Keep the edge by concentrating on the differentiating factors and focusing on our strengths

10. ITU-T Study Group 17 What about UML? UML is generic, SDL/MSC/TTCN are specific UML is generic, SDL/MSC/TTCN are specific SDL and MSC experts key for UML 2.0 SDL and MSC experts key for UML 2.0 Tools for joint support available Tools for joint support available UML without SDL is like a car without an engine UML without SDL is like a car without an engine Co-operation with OMG in progress Co-operation with OMG in progress If you really want UML, you can use it without losing the benefits of SDL/MSC If you really want UML, you can use it without losing the benefits of SDL/MSC

11. ITU-T Study Group 17 What about XML? ASN.1 + XCN (XML Control Notation) ASN.1 + XCN (XML Control Notation)  as powerful and expressive as XSD (XML Schema Definition)  less verbose and much more readable. ASN.1 is a mature schema notation for XML. No schema mapping is needed ASN.1 is a mature schema notation for XML. No schema mapping is needed ASN.1/XER: efficient binary encodings with XML (+ XSL) display (or transfer if needed) ASN.1/XER: efficient binary encodings with XML (+ XSL) display (or transfer if needed) CXER èASN.1/XER as a canonical variant of XER for secured transactions CXER èASN.1/XER as a canonical variant of XER for secured transactions XER tools : http://asn1.elibel.tm.fr/links/#xml XER tools : http://asn1.elibel.tm.fr/links/#xml

12. ITU-T Study Group 17 ASN.1, MSC, SDL and TTCN support secure, hi-quality standards UML and XML are easy and popular You use the best of two worlds

13. ITU-T Study Group 17 What ITU-Languages do for you Provide a method supported by tools Provide a method supported by tools  Free ASN.1 tools  Free Telelogic reader Allow checking correctness on the fly Allow checking correctness on the fly  Is the behaviour is what you really intended? Improves the quality of the standard Improves the quality of the standard  Interoperability is greatly improved Once used properly, helps save time! Once used properly, helps save time!

14. ITU-T Study Group 17 Obstacles to Language Use Benefit unclear Benefit unclear  Check track record Formality reduces freedom Formality reduces freedom  Freedom only reduced for issues needed for interoperation, use correct dose of formality Quick and dirty is better Quick and dirty is better  Are you going to spend more time later fixing holes?

15. ITU-T Study Group 17 Obstacles to Language Use No expertise in group No expertise in group  Specialists should concentrate on their domain – get support for languages Missing support Missing support  ITU TSB should provide this!  Or ask SG17 – we could e.g. provide tutorials in SDL, ASN.1 etc.  In general: Expertise is available

16. ITU-T Study Group 17 Examples of successful use ASN.1 ASN.1  Intelligent network  GSM  UMTS (3G cellphones)  Voice over IP SDL SDL  IN CS-2 / CS-3  OSPF (IETF)

17. ITU-T Study Group 17 Remaining problems Viewing different levels of abstraction Viewing different levels of abstraction Simplify techniques – lost intuitiveness Simplify techniques – lost intuitiveness Bridge the gap to users without specialist knowledge of formal techniques Bridge the gap to users without specialist knowledge of formal techniques Enable bottom-up Enable bottom-up

18. ITU-T Study Group 17 Tool usage at ITU-T SDT is currently the standard tool at ITU and ETSI SDT is currently the standard tool at ITU and ETSI Recommendation authors send SDT files, which are checked by TSB staff Recommendation authors send SDT files, which are checked by TSB staff Formal descriptions are considered non-copyrighted Formal descriptions are considered non-copyrighted Common Interchange Format CIF is very important (e.g. for those using Cinderella)! Common Interchange Format CIF is very important (e.g. for those using Cinderella)! Availability of cheap or free lightweight tool for standards greatly helps promote SDL/MSC Availability of cheap or free lightweight tool for standards greatly helps promote SDL/MSC  The ITU-T CD-ROM, also available for you all, has been a step in this direction!

19. ITU-T Study Group 17 Professional support is needed! To further improve standards quality, SG17 reinforced the recommendation that TSB provide To further improve standards quality, SG17 reinforced the recommendation that TSB provide  expertise on a regular basis in the ITU-T languages and methodologies concerning the use of the languages  tools, supporting and facilitating the use of ITU- T languages We really need permanently available experts at ITU-T: We really need permanently available experts at ITU-T:  ETSI success story  Demand must come from users

20. ITU-T Study Group 17 Summary of possible actions Understand level of quality and need for formalised techniques Understand level of quality and need for formalised techniques Make tool support available Make tool support available Make professional support available Make professional support available Tools need improvement to cater for users developing standards Tools need improvement to cater for users developing standards Enable constant feedback from users in standards as from industry Enable constant feedback from users in standards as from industry Use the crisis – Start a case study with Q16/11? Use the crisis – Start a case study with Q16/11?

21. ITU-T SG17: http://www.itu.int/ITU-T/studygroups/com17/index.html ASN.1 Consortium: http://www.asn1.org SDL Forum Society: http//www.sdl-forum.org Indian SDL and TTCN Forum: http://www.sdl-ttcnforum.org/ Plenty of information on the web