The present document specifies the Test Suite Structure and Test Purposes (TSS&TP) for the Network side of the T
reference point or coincident S and T reference point (as defined in ITU-T Recommendation I.411 [6]) of
implementations conforming to the stage three standard for the Closed User Group (CUG) supplementary service for
the pan-European Integrated Services Digital Network (ISDN) by means of the Digital Subscriber Signalling System
No. one (DSS1) protocol, EN 300 138-1 [1].
A further part of the present document specifies the Abstract Test Suite (ATS) and partial Protocol Implementation
eXtra Information for Testing (PIXIT) proforma based on the present document. Other parts specify the TSS&TP and
the ATS and partial PIXIT proforma for the User side of the T reference point or coincident S and T reference point of
implementations conforming to EN 300 138-1 [1].