UNE-EN 301067-4V2.1.1

Broadband Integrated Services Digital Network (B-ISDN);Digital Subscriber Signalling System No. two (DSS2) protocol;Connection characteristics;Negotiation during call/connection establishment phase;Part 4: Abstract Test Suite (ATS) and partial Protocol Implementations eXtra Information for Testing (PIXIT) proforma specification for the user (Endorsed by Asociación Espanola de Normalización in September of 2021.)