scope:

This second part of DEN/SPAN-05171 is applicable to the stage three of the Line Hunting (LH) 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 [6]) 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 telecommunication service (see CCITT Recommendation I.130 [5]). The present document provides the Protocol Implementation Conformance Statement (PICS) proforma for the ISDN DSS1 supplementary service interactions protocol as specified in EN 301 484-1 [2] in compliance with the relevant requirements and in accordance with the relevant guidance given in ISO/IEC 9646-7 [4].