An Introductory Overview Anthony Wiles ETSI PTCCETSI STF

An Introductory Overview Anthony Wiles ETSI PTCC/ETSI STF 156 TTCN-3 An Introductory Overview, Copyright ETSI 2000

Presentation Outline 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. Basic Concepts Structure and Contents of a TTCN-3 Test Suite TTCN-3 Data Types Defining Test Data Specifying elements of Test System Architecture Specifying Test System Behaviour TTCN-3 Program Statements and Operations Creating, Building and Controlling Test Configurations Communication Between Test Components TTCN-3 Behaviour Trees 11. Timers, Verdicts and SUT Operations 12. Executing and Controlling Test Cases 13. Specifying Additional Attributes TTCN-3 An Introductory Overview, Copyright ETSI 2000

Basic Concepts TTCN-3 An Introductory Overview, Copyright ETSI 2000

History of TTCN • TTCN: Tree and Tabular Combined Notation • Versions 1 and 2 developed by ISO SC 21 WG 3 (1984 1997) as part of the widely-used ISO/IEC 9646 conformance testing standard – ISO/IEC 9646 -3 and ITU-T X. 292 – Updates/maintenance by ETSI in TR 101 666 (TTCN-2++) • Version 3 developed by ETSI TC MTS (1998 - 2000) – Specialist Task Forces STF 133 & STF 156 TTCN-3 An Introductory Overview, Copyright ETSI 2000 4

TTCN-3 Standard Documents • Three-part ETSI Standard (ES) – DES/MTS-00063 -1 : Core Language TTCN-3 – DES/MTS-00063 -2 : Tabular Presentation Format – DES/MTS-00063 -3 : MSC Presentation Format • ITU-T equivalents Z. 140, Z. 141, Z. 142 • Additional Documents – DTR/MTS-00069 : TTCN-2 to TTCN-3 Mapping – DTS/MTS-00070 : Library of Predefined Functions TTCN-3 An Introductory Overview, Copyright ETSI 2000 5

Motivation for Producing TTCN -3 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 TTCN-3 An Introductory Overview, Copyright ETSI 2000 6

Main Capabilities of TTCN-3 • 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 TTCN-3 An Introductory Overview, Copyright ETSI 2000 7

The Core Language Text format Tabular Format TTCN-3 Core Language MSC Format Presentation Format 3 Presentation Formatn TTCN-3 An Introductory Overview, Copyright ETSI 2000 • Core format is a text based language • Core can be viewed as text or in various presentation formats • Tabular format for conformance testing • Message Sequence Chart (MSC)format • Other standardized formats in the future • Proprietary formats 8

Example Core (Text) Format function PO 49901(integer FL) runs on My. MTC { L 0. send(A_RL 3(FL, CREF 1, 16)); TAC. start; alt { [] L 0. receive(A_RC 1((FL+1) mod 2)) { TAC. cancel; verdict. set(pass) } [] TAC. timeout { verdict. set(inconc) } [] any. receive { verdict. set(fail) } } END_PTC 1() // postamble as function call } TTCN-3 An Introductory Overview, Copyright ETSI 2000 9

Example Tabular Format TTCN-3 An Introductory Overview, Copyright ETSI 2000 10

Example MSC Format TTCN-3 An Introductory Overview, Copyright ETSI 2000 11

Use With Other Languages ASN. 1 Types & Values Other types & Values 2 • TTCN can be integrated with other 'type and value' systems TTCN-3 Core Language • Fully harmonized with ASN. 1 (1997) • Harmonization possible with other type and value systems (possibly from proprietary languages) Other types & Valuesn TTCN-3 An Introductory Overview, Copyright ETSI 2000 12

Major Elements of TTCN-3 Core Data Types Test Data Test System Architecture Test Behaviour • Built-in and user-defined generic data types (e. g. , to define messages, service primitives, information elements, PDUs) • Actual test data transmitted/received during testing • Definition of the components and communication ports that are used to build various testing configurations • Specification of the dynamic test system behaviour TTCN-3 An Introductory Overview, Copyright ETSI 2000 13

Structure and Contents of a TTCN-3 Test Suite TTCN-3 An Introductory Overview, Copyright ETSI 2000

TTCN-3 Modules Module (…) Module Definitions Module Control Attributes • Modules are the building blocks of all TTCN-3 specifications • A test suite is a module • A module has a definitions part and a control part • Modules can be parameterised • Modules can import definitions from other modules • Modules can have attributes TTCN-3 An Introductory Overview, Copyright ETSI 2000 15

Example of Module Structure module My. Module (integer My. TSPar 1) { : // Definitions part control { : } // Control part } with display “ETSI format”; TTCN-3 An Introductory Overview, Copyright ETSI 2000 16

Module Definitions Data Types Constants RP Signatures Data Templates Signature Templates Communication Ports Test Components Functions Named Alternatives • Definitions are global to the entire module • Data Type definitions are based on the TTCN-3 predefined types • Templates and Signatures define the test data • Ports and Components are used in Test Configurations • Functions, Named Alts and Test Cases define behaviour Test Cases TTCN-3 An Introductory Overview, Copyright ETSI 2000 17

Importing Definitions // Importing single definitions import template My. Template from My. Module; // Importing definitions of the same kind import all template from My. Module; // Importing all definitions import all from My. Module; // inhibiting recursive import template My. Template from My. Module nonrecursive; /* To avoid name clashes the imported definition is prefixed with the identifier of the source module */ TTCN-3 An Introductory Overview, Copyright ETSI 2000 18

External Definitions // External constants may be defined external const integer My. External. Const; // External functions may be defined external function My. Function 4() return integer; TTCN-3 An Introductory Overview, Copyright ETSI 2000 19

Groups of Definitions // A nested group of function group My. Test. Step. Library { group My. Group 1 { function My. Test. Step 11 { : function My. Test. Step 1 n { } group My. Group 2 { function My. Test. Step 21 { : function My. Test. Step 2 n { } } TTCN-3 An Introductory Overview, Copyright ETSI 2000 definitions … } … } 20

TTCN-3 Data Types TTCN-3 An Introductory Overview, Copyright ETSI 2000

TTCN-3 Base Types TTCN-3 An Introductory Overview, Copyright ETSI 2000 22

Example of Integer Type /* integer sub-type RANGE definition */ type integer My. Integer. Range (1. . 100) type integer My. Integer. Range (0. . infinity) /* integer sub-type LIST definition */ type integer My. Integer. List (1 , 2, 3, 4) /* integer sub-type as a mixed LIST and RANGE */ type integer My. Integer. List. And. Range (1. . 5, 7, 9) TTCN-3 An Introductory Overview, Copyright ETSI 2000 23

Example of a Structured Type // record type definition type record My. Message. Type { integer field 1 optional, boolean field 2 } // record value notation var My. Message. Type My. Message { field 1 1, field 2 true } // Individual field assignment My. Message. field 2 : = false TTCN-3 An Introductory Overview, Copyright ETSI 2000 24

Arrays /* Arrays are not considered to be types in TTCN-3. Instead, they are specified at the point of variable declaration */ // integer array of 5 elements var integer My. Array[5]; // indexing starts at zero My. Array[0]: = 1; // An initialiser may be used to set array values My. Array : = {1, 2, 3, 4, 5}; TTCN-3 An Introductory Overview, Copyright ETSI 2000 25

ASN. 1 Type Compatibility • The following ASN. 1 types are considered to be equivalent to their TTCN-3 counterparts • TTCN-3 value notation, operators etc. may be used on values of these types a TTCN module ASN. 1 types INTEGER BOOLEAN OBJECT IDENTIFIER BIT STRING OCTET STRING SEQUENCE OF SET OF ENUMERATED CHOICE TTCN types integer boolean objectidentifier bitstring octetstring sequence of set of enumerated union TTCN-3 An Introductory Overview, Copyright ETSI 2000

Defining Test Data TTCN-3 An Introductory Overview, Copyright ETSI 2000

Different Uses of Data in TTCN-3 Test Specifications • Data in TTCN-3 is used – internally to the test component – as information passed between test components within the test system – as test data transmitted to and received from the System Under Test (SUT) • The grouping mechanism can be used to collect data definitions of a similar ‘kind’ e. g. , – Service Primitives (ASP) – Protocol Data Units (PDU) – internal coordination messages TTCN-3 An Introductory Overview, Copyright ETSI 2000 28

Constants (and Variables) /* Constants are defined in the definitions part of a module (and inside functions and test components) */ constant integer My. Constant : = 1; /* Variables can only be declared in the module control part (and inside functions and test components) TTCN-3 does not support global variables */ var hexstring My. Hex. String; TTCN-3 An Introductory Overview, Copyright ETSI 2000 29

Example Message Definition // Complex messages can be defined by records Type record My. Message. Type My. Message : = { field 1 integer optional, field 2 integer, field 3 integer, field 4 integer, field 5 boolean optional, field 6 hexstring optional, field 7 Another. Message. Type, field 8 bitstring, field 9 charstring (1. . 20) } TTCN-3 An Introductory Overview, Copyright ETSI 2000 30

Data Templates • Templates are special data values that have the following characteristics – matching mechanisms – they can be parameterised – they can be modified to provide a simple form of inheritance • Templates can be applied to simple types as well as complex types • Are most often used to define the possible received values of messages and responses to remote procedure calls TTCN-3 An Introductory Overview, Copyright ETSI 2000 31

Matching Mechanisms TTCN-3 An Introductory Overview, Copyright ETSI 2000 32

Examples of Simple Templates /* Template for a simple integer type */ template integer My. Data 1 : = *; template integer My. Data 2 : = (1, 2, 3); /* This line in a test behaviour description will match any incoming integer value */ P 1. receive(My. Data 1); /* This line will match on one of the incoming integer values 1, 2 or 3 */ P 1. receive(My. Data 2); TTCN-3 An Introductory Overview, Copyright ETSI 2000 33

Example Message Template template My. Message. Type My. Message : = { field 1 1 ifpresent, field 2 (1, 2, 3), field 3 (0. . 255), field 4 not (1, 2, 3), field 5 omit, field 6 * ifpresent, field 7 ? , field 8 ‘ 1011? 110*1’B, field 9 “abc” <*> “xyz” length (20) } TTCN-3 An Introductory Overview, Copyright ETSI 2000 34

Parameterised Templates (1) // Value parameterisation template My. Message. Type My. Message (integer My. Par) : = { field 1 My. Par, field 2 true field 3 ‘ 110011’B } // Example use of this template P 1. send(My. Message(1)); TTCN-3 An Introductory Overview, Copyright ETSI 2000 35

Parameterised Templates (2) // Type parameterisation type record My. Record. Type(My. Meta. Type) { boolean field 1, My. Meta. Type field 2 // field 2 type not defined } var My. Record. Type(integer) My. Record. Value : = { field 1 : = true, field 2 : = 123 // field 2 now of type integer } TTCN-3 An Introductory Overview, Copyright ETSI 2000 36

Modified Templates // Writing template My. Message. Type My. Message 1 { field 1 123, field 2 true } // and template My. Message. Type My. Message 2 modifies My. Message 1 { field 2 false } // Is the same as writing template My. Message. Type My. Message 3 { field 1 123, field 2 false } TTCN-3 An Introductory Overview, Copyright ETSI 2000 37

Local Function Definitions /* Functions can declare local constants, variables and timers */ function My. Function { const hexstring My. Const : = ‘FF 00’H; var integer My. Var : =1; timer My. Timer; : } TTCN-3 An Introductory Overview, Copyright ETSI 2000 38

Procedure Signatures /* Procedure signatures are needed for synchronous communication over procedure-based ports (remote procedure calls) */ signature My. Remote. Proc ( in integer Par 1, out float Par 2, inout integer Par 3 ) return integer exception (Except. Type 1, Except. Type 2); TTCN-3 An Introductory Overview, Copyright ETSI 2000 39

Signature Templates signature My. Remote. Proc ( in integer Par 1, out float Par 2, inout integer Par 3 ) return integer exception (Except. Type 1, Except. Type 2); /* templates may be used to define the actual parameters to a remote procedure call */ template My. Remote. Proc Mytemplate : = { Par 1 : = 7, Par 2 : = *, Par 3 : = My. Const } TTCN-3 An Introductory Overview, Copyright ETSI 2000 40

Specifying Elements of Test System Architecture TTCN-3 An Introductory Overview, Copyright ETSI 2000

Test Components Test Component Local Declarations Ports Used • Test components are the entities on which test behaviour is executed (in parallel) • Declarations may be made locally in the component • A list of the ports used by the component must also be given • Actual configurations are built dynamically in the test behaviour using operations such as create, connect etc. TTCN-3 An Introductory Overview, Copyright ETSI 2000 42

Kinds of Test Components • There are three ‘kinds’ of component – MTC (Main Test Component) – PTC (Parallel Test Component) – a PTC that defines the Abstract Test System Interface Abstract Test System MTC 1 PTC 2 PTCn Abstract Test System Interface Real test system connected to an SUT TTCN-3 An Introductory Overview, Copyright ETSI 2000 43

Communication Ports • Test components communicate via communication ports • A test port is modeled as an infinite FIFO queue • Ports have direction (in, out, inout) • There are three types of port – message-based, procedure-based or mixed PTC 1 P 1 (out) P 1 (in) P 1. send(Msg) TTCN-3 An Introductory Overview, Copyright ETSI 2000 PTC 2 P 1. receive(Msg) 44

Example Port Definition // Definition of a message-based port type port My. Message. Port. Type message { in Msg. Type 1, Msg. Type 2; out Msg. Type 3; inout integer } // Definition of a procedure-based port type port My. Procedure. Port. Type procedure { out Procedure. Signature 1, Procedure. Signature 2 } TTCN-3 An Introductory Overview, Copyright ETSI 2000 45

Example Component Definition // Definition of test component type component My. Component. Type { // Local declarations var integer My. Var; timer My. Timer; // Ports used by the component My. Message. Port. Type P 1, P 2; My. Procedure. Port. Type P 3 } TTCN-3 An Introductory Overview, Copyright ETSI 2000 46

Test System Interface /* A user-defined component that defines the port interface to the underlying real test system */ type component My. Test. System. Inteface. Type { My. Lower. PCOType LT; My. Upper. PCOType UT } TTCN-3 An Introductory Overview, Copyright ETSI 2000 47

Specifying Test System Behaviour TTCN-3 An Introductory Overview, Copyright ETSI 2000

TTCN-3 Functions Function (. . . ) Local Declarations Program Part • Functions are the building-blocks of test system behaviour • Functions have local declarations and a program part • Can be a 'pure' function doing some internal test system task or specify test behaviour using communication operations such as send and receive • External functions are allowed • There are some pre-defined functions (type conversion etc. ) TTCN-3 An Introductory Overview, Copyright ETSI 2000 49

Pre-defined Functions TTCN-3 An Introductory Overview, Copyright ETSI 2000 50

Function Definitions(1) // Functions can be parameterised // in, out, inout paramters. Default is in function My. Function (in integer My. Par) { : } // Functions can return values // Default is void function My. Function return integer { : } TTCN-3 An Introductory Overview, Copyright ETSI 2000 51

Function Definitions(2) /* This function performs a generic task. It does not use any communication operations */ function My. Function { : } /* This function uses communication operations consistent with the ports offered by My. PTC */ function My. Function runs on My. PTC { : } TTCN-3 An Introductory Overview, Copyright ETSI 2000 52

Test Case Definitions Test Case (. . . ) Interface Part System Part Behaviour Part • Test cases are a special kind of function executed in the control part of a module • The interface part (runs on) references the MTC on which the test case will run • The system part (system) references the test system interface component. Can be omitted if the test case only consists of an MTC • The Behaviour part defines test case behaviour TTCN-3 An Introductory Overview, Copyright ETSI 2000 53

Example Test Case Definitions // Parallel configuration testcase My. Test. Case() runs on My. MTCType system My. Test. System. Type { : // behaviour defined here } // Configuration consists only of an MTC testcase My. Test. Case()runs on My. MTCType { : // behaviour defined here } TTCN-3 An Introductory Overview, Copyright ETSI 2000 54

TTCN-3 Program Statements and Operations TTCN-3 An Introductory Overview, Copyright ETSI 2000

Kinds of Statements and Operations TTCN-3 An Introductory Overview, Copyright ETSI 2000 56

Basic Program Statements TTCN-3 An Introductory Overview, Copyright ETSI 2000 57

Example Program Statement function My. Function { var integer x, j; for (j: =1; j<=10; j: =j+1) { if (My. Global. Flag == true) { x: =j*2; log int 2 str(x); } else x : = j*3 } } TTCN-3 An Introductory Overview, Copyright ETSI 2000 58

Operators TTCN-3 An Introductory Overview, Copyright ETSI 2000 59

Creating, Building and Controlling Test Configurations TTCN-3 An Introductory Overview, Copyright ETSI 2000

Configuration Operations TTCN-3 An Introductory Overview, Copyright ETSI 2000 61

Creating Components • The MTC is the only component that is automatically created when the test case is executed – all PTCs must be created explicitly using the create operation • The create operation returns the unique component reference for the newly created component • Components can be created at any point in a behaviour description TTCN-3 An Introductory Overview, Copyright ETSI 2000 62

Example of Create // Define a variable of type component My. Component. Type { : } // Define a variable of type component var My. Component. Type My. Component; // create the component My. Component : = Mycomponent. Type. create TTCN-3 An Introductory Overview, Copyright ETSI 2000 63

Connecting and Mapping Components Test System IN My. MTC Connected Ports OUT P 1 OUT My. PTC IN OUT Mapped Ports Abstract Test System Interface OUT P 2 IN PCO IN Real Test System Interface SUT TTCN-3 An Introductory Overview, Copyright ETSI 2000 64

Example of Connect and Map /* The connect operation is used to connect components within the test system */ connect(My. PTC: P 1, mtc: P 1) /* The map operation is used to ‘connect’ components to the abstract test system interface */ map(My. PTC: P 2, system: PCO) TTCN-3 An Introductory Overview, Copyright ETSI 2000 65

Communication Between Test Components TTCN-3 An Introductory Overview, Copyright ETSI 2000

Asynchronous Communication send receive MTC PTC non-blocking TTCN-3 An Introductory Overview, Copyright ETSI 2000 67

Asynchronous Communication Operations TTCN-3 An Introductory Overview, Copyright ETSI 2000 68

Examples of Asynchronous Communication Operations My. Port. send(integer: 5); My. Port. receive(My. Template(5, My. Var)); My. Port. receive(A<B) from My. Partner; My. Port. receive(My. Type: *) -> value My. Var; My. Port. receive(integer: 5) -> sender My. Peer; TTCN-3 An Introductory Overview, Copyright ETSI 2000 69

Synchronous Communication call getcall PTC MTC getreply or catch exception reply or raise exception blocking TTCN-3 An Introductory Overview, Copyright ETSI 2000 blocking 70

Synchronous Communication Operations TTCN-3 An Introductory Overview, Copyright ETSI 2000 71

Examples of Synchronous Communication Operations // Calling a remote procedure My. Port. call (My. Proc, 30 ms) to My. Peer { [] My. Port. getreply(My. Proc) -> value My. Result; [] My. Port. catch (My. Proc, Exception 1) } // Replying to a remote procedure My. Port. reply (My. Proc) TTCN-3 An Introductory Overview, Copyright ETSI 2000 72

TTCN-3 Behaviour Trees TTCN-3 An Introductory Overview, Copyright ETSI 2000

Behaviour Statements TTCN-3 An Introductory Overview, Copyright ETSI 2000 74

Behaviour Statements // Sequential statements are denoted by a semi-colon function My. Function 1 { My. Function 2; x: =x+1; My. Port. receive(my. Message); // Blocks execution until message received My. Port. send(My. Message) } TTCN-3 An Introductory Overview, Copyright ETSI 2000 75

Alternative Behaviour • Alternative behaviour is defined using the alt statement • alt statements may only be the receiving communication operations and timer events – receive, trigger, getcall, getreply, catch, check, timeout S 1 S 3 S 2 S 4 S 5 S 7 S 6 S 8 S 9 S 10 S 1; alt {[ ] S 3; S 6; [ ] S 2; alt { [ ] S 4; S 7; [ ] S 5; S 8; alt { [ ] S 9; [ ] S 10; } } } TTCN-3 An Introductory Overview, Copyright ETSI 2000 76

Schematic View of Alternatives • Each alternative consists of – a guard (possibly empty) – an event, and – an (optional) sequence of actions (including further alts) • The TTCN-2 concept of snapshot semantics still applies alt guard 1 event 1 actions 1 guard 2 event 2 actions 2 guardn eventn actionsn TTCN-3 An Introductory Overview, Copyright ETSI 2000 77

Example Alt Statement alt { [] My. Port. receive(My. Message 1) { My. Port. send(My. Message 4) alt { // Next level } } [x>1] My. Port. receive(My. Message 2); [x<1] My. Port. receive(My. Message 3) } TTCN-3 An Introductory Overview, Copyright ETSI 2000 78

Named Alternatives • Named alternatives (named alt) are descriptions of partial alternatives – defined in the module definitions – are named and may be parameterised • Named alternatives are macro-expansions – they are not functions • Can be referenced from anywhere that it is legal to write a normal alt statement • The expand statement allows a named alt to be explicitly expanded inside another set of alternatives TTCN-3 An Introductory Overview, Copyright ETSI 2000 79

Example of Named Alt (1) // Definition in module definitions named alt My. Named. Alt { [] L 1. receive(My. Message 1) [] L 1. receive(My. Message 2) } // Use of the named alt testcase TC 101() { My. Named. Alt() // In-line reference in test case alt { [] L 1. receive(My. Message 3); [expand] My. Named. Alt(); // Macro expansion here } } TTCN-3 An Introductory Overview, Copyright ETSI 2000 80

Example of Named Alt (2) // Is the same as testcase TC 101() { alt { [] L 1. receive(My. Message 1) [] L 1. receive(My. Message 2) } alt { [] L 1. receive(My. Message 3) [] L 1. receive(My. Message 1) [] L 1. receive(My. Message 2) } } TTCN-3 An Introductory Overview, Copyright ETSI 2000 81

Default Behaviour • Default behaviour is defined using named alternatives • Defaults must be explicitly activated and deactivated • The expansion of defaults is applied to the end of the toplevel set of alternatives in an alt statement … • … and to all single receiving operations and timeouts // Note that the single statement L 1. receive(My. Message 1); // is equivalent to alt { [] L 1. receive(My. Message 1)} TTCN-3 An Introductory Overview, Copyright ETSI 2000 82

Activate and Deactivate named alt My. Default { [] L 1. any. receive } // Use of the named alt testcase TC 101() { : activate (My. Default) : // Default applies from here deactivate (My. Default) : // Default does not apply from here } TTCN-3 An Introductory Overview, Copyright ETSI 2000 83

Interleaved Behaviour /* The interleave statement specifies all possible combinations of executing a given set of alternative statements */ interleave { [] PCO 1. receive(My. Message. One); [] PCO 1. receive(My. Message. Two); [] PCO 1. receive(My. Message. Three); } TTCN-3 An Introductory Overview, Copyright ETSI 2000 84

Timers, Verdicts and SUT Operations TTCN-3 An Introductory Overview, Copyright ETSI 2000

Additional Operations TTCN-3 An Introductory Overview, Copyright ETSI 2000 86

Verdicts • Verdicts: pass, fail, inconc, none, error • each test components has its own local verdict – can be written (set) and read (get) • Global verdict returned by Test Case (read-only) Verdict returned by the test case when it terminates V MTC V verdict. set(fail) PTC 1 V verdict. set(pass) TTCN-3 An Introductory Overview, Copyright ETSI 2000 PTC 2 V verdict. set(inconc) 87

Timer Operations // Starting, stopping and reading a timer My. Timer. start(20 E-3)// Default unit is secs My. Timer. stop My. Var : = My. Timer. read // Check if a timer is running if (My. Timer. running) { … } // timeout in an alternative : [] My. Timer. timeout : TTCN-3 An Introductory Overview, Copyright ETSI 2000 88

Executing and Controlling Test Cases TTCN-3 An Introductory Overview, Copyright ETSI 2000

Module Control Local Control Declarations Test Case Execution • Module control is the ‘dynamic’ part of a TTCN-3 specification where test cases are executed (execute) • Local declarations, such as variables and timers may be made in the control part • Basic programming statements may be used to select and control the execution of the test cases TTCN-3 An Introductory Overview, Copyright ETSI 2000 90

Local Control Declarations : control { const hexstring My. Const : = ‘FF 00’H; var integer My. Var : =1; timer My. Timer; : } : TTCN-3 An Introductory Overview, Copyright ETSI 2000 91

Executing Test Cases Module My. Module { // Test cases are defined in the module definitions testcase My. Test. Case() runs on My. MTC system My. Test. System { // behaviour defined here } control { // and executed in the control part execute (My. Test. Case()) } } TTCN-3 An Introductory Overview, Copyright ETSI 2000 92

Controlling Test Cases // Test Cases return verdicts execute(My. Test. Case()) -> value My. Verdict; // Timeouts may be placed on Test Cases execute(My. Test. Case(), 0. 5) -> value My. Verdict; // Test Cases can be used with program statements while (x<10) { x: =x+1; execute(My. Test. Case()) } // Selection of Test Cases if (My. Selection. Expression) execute(My. Test. Case()) TTCN-3 An Introductory Overview, Copyright ETSI 2000 93

Specifying Additional Attributes TTCN-3 An Introductory Overview, Copyright ETSI 2000

Defining Attributes Language Element • Special attributes can be associated with most TTCN-3 language elements using the with statement • encoding information (encode) – standardized: ASN. 1 – application specific, proprietary • display information (display) – standardized: tabular and MSC formats Attributes – or proprietary • user-defined (extension) – proprietary TTCN-3 An Introductory Overview, Copyright ETSI 2000

Example Attributes type record { integer ia 5 string boolean } with { display encode extension } My. PDU field 1, field 2, field 3 “ETSI Tabular : = PDU”; // Tabular PDU “BER”; // Encoding directive “My. Rule” // User specific TTCN-3 An Introductory Overview, Copyright ETSI 2000 96

An Introductory Overview The End TTCN-3 An Introductory Overview, Copyright ETSI 2000

… or just the beginning? TTCN-3 An Introductory Overview, Copyright ETSI 2000