INTERNATIONAL  TELECOMMUNICATION  UNION

		     ITU-T RECOMMENDATION SUMMARY


Rec. No. : X.291

Title :	OSI conformance testing methodology and framework for protocol
	recommendations for CCITT applications - abstract test suite 
	specifications

Study Group : VII - Data Communications Networks

Version : New

Date of adoption : 1992

Notes : Also published as ISO/IEC 9646-2: 1991


Recommendation X.291 provides a common approach to the specification 
of OSI conformance test suites at a level which is independent of the 
means of executing those test suites (hereafter called "abstract test 
suites").  This level of abstraction is suitable for standardization 
and facilitates the comparison of results produced by different 
organizations which run the corresponding executable test suites. 
It recalls that there are requirements on OSI protocol specifiers 
which have to be fulfilled before there can be an objective basis for 
the process of developing an abstract test suite. The need is 
expressed for consistent conformance clauses and for PICS proformas in 
CCITT Recommendations or International Standards which specify OSI 
protocol standards. 

It describes the process of developing an abstract test suite, 
including the design criteria to be used and guidance on its structure 
and coverage. The possible abstract test methods are defined and 
guidance is given to help the test suite specifier to decide which 
test method(s) to use in the production of a particular test suite.  
Requirements and guidance are given on the specification of abstract 
test cases. These include the subdivision of test cases into test 
steps and the assignment of test verdicts to test outcomes. 

The test suite specifier is also required to provide information to 
the test realizers (e.g. limitations governing test case selection). 

Finally, guidance and requirements are given on test suite 
maintenance. 

Recommendation X.291 specifies the requirements and gives guidance for 
the production of system-independent conformance test suites for one 
or more OSI CCITT Recommendations or International Standards. In 
particular, it is applicable to the production of all conformance 
testing standards for OSI and ISDN two-party protocols, including all 
draft versions of such conformance testing standards.

Recommendation X.291 is applicable to the production of conformance 
test cases which check the conformance of an implementation to the 
relevant static and/or dynamic conformance requirements by controlling 
and observing protocol behaviour. The Abstract Test Methods included 
in Recommendation X.291 are, in fact, capable of being used to specify 
any test case which can be expressed abstractly in terms of control 
and observation of Protocol Data Units and Abstract Service 
Primitives. Nevertheless, for some protocols, test cases may be needed 
which cannot be expressed in these terms. The specification of such 
test cases is outside the scope of Recommendation X.291, although the 
test cases may themselves need to be included in a conformance testing 
standard. For example, some static conformance requirements related to 
an Application service element may require testing techniques which 
are specific to that particular Application.



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