Telematics group University of Göttingen, Germany Integrated Application of TTCN Dieter Hogrefe.

Telematics groupUniversity of Göttingen, Germany

Integrated Application of TTCN

Dieter Hogrefe

2SG17 workshop, Sep. 2003


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alt { [] A.receive(Y); …

[] myT.timeout; …}

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Peculiarities of Communication Software (Protocols) vs. other types Software

1) Establishment of states (connection, interface, process) -> state oriented modelling

2) Precisely defined and standardized message formats

3) The software has to interwork with a large amount of (unknown) implementations

4) Distribution



Consequences from the peculiarities

1) Existence of detailed specifications (Internet Draft, ETSI Standard, ITU-T Standard, Proprietary, …)Base Standards and Test Specifications

2) Specialized (state oriented) specification languages and methods have been developed

3) Testing against reference implementations (protocol testers

4) Testing by Interop events, e.g.IPv6 Event, Mandelieu, 23-27 Sep.



Specialized specification languages, methods and tools

1) Languages:SDL, MSC, TTCN, ASN.1, (UML in the future?)

2) Methods:- State based modelling- State based verification (e.g. state space exploration)- Systematic test case development based on specialized methodology (ISO 9646, UIO, …)

3) Tools:Telelogic TAU, Solinet SAFIRE, DANET, DaVinci, TestingTech, …



Testing Language http://www.etsi.org/ptcc/ptccttcn3.htm

• Testing and Test Control Notation • Versions 1 and 2 developed by ISO SC21 WG3

(1984 - 1997) as part of the widely-used ISO/IEC 9646 conformance testing standard– ISO/IEC 9646-3 (edition 2) and ITU-T X.292

• Version 3 developed by ETSI TC MTS (1998 - 2000)– Specialist Task Forces STF 133 & STF 156



Testing Language

• One test notation for many testing applications• Cheaper education and training costs• Facilitates the application of a common methodology• Easier maintenance of test suites• Off-the-shelf tools• Universally understood syntax and operational

semantics• Tests concentrate on the meaning of the test• Constant maintenance of the language



Motivation for developing

• Modernization – technology has changed since TTCN was first developed

• Wider scope of application– should be applicable to many kinds of test applications

not just conformance (development, system, integration, iop …)

• Harmonization– should be the first choice for test specifiers, implementors

and users both for standardized test suites ...– … and as a generic solution in industrial product

development



Testing Language

– Kinds of testing to which TTCN-3 could be applied • - Conformance - Interoperability• - Configuration - Compatibility• - Performance - Stress• - Robustness - Integration• - Functional - Load• - Reliability - Fault tolerance• - Scalability - Degraded mode• - Unit - Product• - Development - Design• - Interface - System



Main Capabilities of

• Dynamic concurrent testing configurations• Various communication mechanisms (synch and asynch)• Data and signature templates with powerful matching

mechanisms• Specification of encoding information• Display and user-defined attributes• Test suite parameterization• Test case control and selection mechanisms• Assignment and handling of test verdicts• Harmonized with ASN.1• Different presentation formats• Well-defined syntax, static semantics and operational

semantics



Core Language

PresentationFormat3

PresentationFormatn

TTCN-3 Core Language

Text format

Graphical Format

Tabular Format

• Core format is a text based language

• Core can be viewed as text or in various presentation formats

• Tabular format for conformance testing

• Other standardized formats in the future

• Proprietary formats

• Graphical format for visual overview



Use with other Languages

TTCN-3 Core Language

Other types & Values2

Other types & Valuesn

ASN.1 Types & Values

• TTCN can be integrated with other 'type and value' systems

• Harmonization possible with other type and value systems (possibly from proprietary languages)

• Fully harmonized with ASN.1 (1997)



Major Elements of

Test Behaviour

Test System Architecture

• Built-in and user-defined generic data types (e.g., to define messages, service primitives, information elements, PDUs)

TTCN-3 Core

Test Data

Data Types

• Specification of the dynamic test system behaviour

• Definition of the components and communication ports that are used to build various testing configurations

• Actual test data transmitted/received during testing



Example Core (Text)

function PO49901(integer FL) runs on MyMTC {

L0.send(A_RL3(FL,CREF1,16));TAC.start;alt {

[] L0.receive(A_RC1((FL+1) mod 2)) { TAC.cancel;

verdict.set(pass)

}

[] TAC.timeout { verdict.set(inconc)

}

[] any.receive { verdict.set(fail) }

}END_PTC1() // postamble as function call

}



Example Tabular

Test Case Definition

Name : MyTestcase

Group :

Purpose : Example Testcase

System I/f :

MTC Type : MyComponentType

Comments :

Name Type Initial Value Comments

MyVar INTEGER 0

Behaviour Definition Comments alt { [ ] MyPort.receive(Msg); [ ] : }

DetailedComments:



Example Graphical



Use of for OSP

• Open Settlement Protocol (OSP)

– EP TIPHON XML-based protocol

– uses TTCN-3 Core Language



Use of for SIP Tests

• IETF Session Initiation Protocol (SIP)

– RFC 3261

– EP TIPHON SIP Profile

• Work was done by STF196 in EP TIPHON– Nokia, Ericsson, GMD Fokus (Testing Tech), ACACIA,

FSCOM, GN Nettest– work due to finish December 2003– executable tests running

• TTCN-3 will be used by 3GPP for SIP tests in 2004



Use of for IP Tests

ETSI has work items on developing test suites for

• IPv6 Core

• IPv6 Security

• IPv4-to-v6 Transition

Currently under review by DG Enterprise at the Commission for funds from the eEurope initiative

WIs for SIGTRAN M3UA, SCTP will be opened in October



Methodology



Methodology

Process P1

Process P2

SDL

Implementation Under Test

(IUT)

ENV1!a

?TIMEOUT Timer

START Timer ENV1?c

ENV1!d ENV2?b

?TIMEOUT Timer

Behaviour Description

fail fail pass

Verdi

ct

TTCN derive

is basis for

test Tester

is basis for



Methodology

• UML testing profile

– TTCN-3 compatible

– JUnit compatible

• UML-TTCN-3 profile?



Goals of the UML Testing Profile

• Definition of a testing profile to capture all information that would be needed by different test processes

– To allow black-box testing (i.e. at UML interfaces) of computational models in UML

• A testing profile based upon UML 2.0

– That enables the test definition and generation of structural (static) and behavioral (dynamic) aspects of UML models, and

– That is capable of inter-operation with existing test technologies for black-box testing

• Define

– Test purposes for computational UML models, which should be related to relevant system interfaces

– Test components, test configurations and test system interfaces

– Test cases in an implementation independent manner



Roots of the Testing Profile P

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MSC-2000 UML 1.x SDL-2000MSC-2000

UML 2.0Graphical Format

of TTCN-3

UML Testing Profile

• Test control• Wildcards• Defaults• Test components

• Arbiter• Validation actions • Data pools



Concepts of the Testing Profile

• Test architecture

– Test structure, test components and test configuration

• Test data

– Data and templates used in test procedures

• Test behavior

– Dynamic aspects of test procedures

• Test time

– Time quantified definition of test procedures



Implementations under Development

• Eclipse Project Hyades on an Open Source Trace and Test Framework

– The test part is based on the U2TP standalone metamodel

• Telelogic Tau G2

– The test part is based on the U2TP profile

• Microsoft Visual Studio

• ITEA Project on Advanced Test Methods and Tools TTmedal



In Summary U2TP

• UML Testing Profile provides specification means for test artifacts of systems from various domains

• Enhances UML with concepts like test configuration, test components, SUT, verdict and default

• Seamlessly integrates into UML: being based on UML metamodel, using UML syntax

• Adopted at OMG Technical Meeting, Paris, June 2003

• http://www.fokus.fraunhofer.de/u2tp/



The End



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Telematics group University of Göttingen, Germany Integrated Application of TTCN Dieter Hogrefe.

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