scope:

This second part of ETS 300 058 is applicable to the stage three of the Call Waiting (CW) supplementary service for the pan-European Integrated Services Digital Network (ISDN) as provided by European public telecommunications operators at the T reference point or coincident S and T reference point (as defined in ITU-T Recommendation I.411 [10]) by means of the Digital Subscriber Signalling System No. one (DSS1) protocol. Stage three identifies the protocol procedures and switching functions needed to support a telecommunications service (see CCITT Recommendation I.130 [9]).

This ETS provides the Protocol Implementation Conformance Statement (PICS) proforma for the ISDN DSS1 CW supplementary service protocol as specified in ETS 300 056 [1] (stage one), ETS 300 0572 [2] (stage two) and ETS 300 058-1 [3] (stage three) in compliance with the relevant requirements and in accordance with the relevant guidance given in ISO/IEC 9646-7 [8].