1

Structuring Test Purposes for Pattern Matching

Some first thoughts from STF256

Steve Randall

TC-MTS, Sophia Antipolis 23-25 March 2004

38TD11r1 ETSI/MTS(04)#38 Sophia Antipolis 23-24 March 2004

Apr 20, 2023 TC-MTS#38 23-25 March 2004038TD11

2

Background

Patterns Group identified need for TP structure STF256 preparing ground for IPv6 testing project.

Includes: TTCN-3 Library Guidance on methods and style

Useful to write TPs in a structured way even if patterns support not available at start of project

Short study carried out within STF256

Apr 20, 2023 TC-MTS#38 23-25 March 2004038TD11

3

TP Format

Consideration given to graphical and textual forms GFT/MSC an obvious choice but lacks flexibility to

express TP fully Textual “pseudo-code” has defined structure and

flexibility Case studies of existing ISDN and HiperAccess TPs

showed that textual approach could work Initial response from experienced testers ranges from

not unfavourable to enthusiastic

Apr 20, 2023 TC-MTS#38 23-25 March 2004038TD11

4

First thoughts on Keywords

Case studies identified the following candidates as keywords:

accepts containing ensure that enters

ignores indicating on receipt rejects

remains sends then valid

via when withwithout

List is very provisional and will change as project progresses

Apr 20, 2023 TC-MTS#38 23-25 March 2004038TD11

5

Examples (1a)

Original TP:

L3U_U00_V_005 subclause 5.2.3.1

Ensure that the IUT in the Null call state U00, on receipt of a valid SETUP message (delivered via the point-to-point data link) with the Channel identification information element indicating a B-channel and indicating in the preferred/exclusive bit "indicated channel is preferred", when no B-channel is available, sends a RELEASE COMPLETE message with a Cause information element indicating the cause value 34 "no circuit/channel available" and remains in the Null call state.

Apr 20, 2023 TC-MTS#38 23-25 March 2004038TD11

6

Examples (1b)

Structured TP:

TPID L3U_U00_V_005base standard ETS 300 403-1subclause 5.2.3.1PICS ETS 300 403-3status mandatory(---)ensure that { when { the IUT is in the Null call state U00 and a valid SETUP message is received via the point-to-point data link with { the Channel identification information element indicating a B-channel and the preferred/exclusive bit indicating "indicated channel is preferred" and no B-channel is available } then { IUT sends a RELEASE COMPLETE message with { a Cause information element indicating cause value 34_ ("no circuit/channel available") } and remains in the Null call state } } }

Apr 20, 2023 TC-MTS#38 23-25 March 2004038TD11

7

Examples (2a)

TP ID SS

Reference clause 7.2.4.4; Table 270

Selection criteria

Test purpose The IUT has transmitted a valid Auth Info message followed by a valid Auth Request message. It has then received a valid Auth Reply message with a T_AuthGrace and T_AKlifetime values different than the default values in Table 270. The IUT is now authorized.

Check that the IUT: For re-authorization, transmits a valid Auth Request message more than (T_AKlifetime – T_AuthGrace) seconds after receiving the Auth Reply but less than T_AKlifetime seconds after receiving the same Auth Reply.

Apr 20, 2023 TC-MTS#38 23-25 March 2004038TD11

8

Examples (2b)

TPID

base standard

subclause 7.2.4.4; Table 270

PICS

status

(---)

ensure that {

when { Negotiate Basic Capabilities is complete

and a valid Auth Info message is sent by the IUT

and a valid Auth Request message is sent by the IUT

and a valid Auth Reply message is received by the IUT

with {T_AuthGrace and T_AKLifetime set to non-default values_(Table 270) } }

then {

IUT sends a valid Auth Request message

after (T_AKlifetime – T_authGrace) seconds

but before T_AKlifetime seconds }}

Apr 20, 2023 TC-MTS#38 23-25 March 2004038TD11

9

Examples (2c)

TPID

base standard

subclause 7.2.4.4; Table 270

PICS

status

(---)

ensure that {

when { Negotiate Basic Capabilities is complete

and IUT is authorized }

then {

IUT sends a valid Auth Request message

after (T_AKlifetime – T_authGrace) seconds

but before T_AKlifetime seconds }}

Apr 20, 2023 TC-MTS#38 23-25 March 2004038TD11

10

Disclaimers!

It is important to consider the following when reviewing this proposal:

1. this is at a very, very early stage and has not been discussed widely

2. the list of key words and phrases is sure to grow as more TPs are analyzed

3. the notation is not meant to be a specification language. It is only intended to provide structure (and thus, pattern) to a TP

4. there is neither syntax nor semantics specified (yet) except what can be implied from the examples

Apr 20, 2023 TC-MTS#38 23-25 March 2004038TD11

11

Next Steps

Extend the scope of analysis to a broader range of existing TPs, particularly IPv6, in order to finalize the list of keywords and basic structure

Work closely with Patterns Group to ensure the notation meets their requirements

Formalize the notation in BNF Discuss possibility of implementation with tool

suppliers Start using it!