| Заглавие на английском языке | Integrated Services Digital Network (ISDN) - Closed User Group (CUG) supplementary service; Digital Subscriber Signalling System No. one (DSS1) protocol - Part 6: Abstract Test Suite (ATS) and partial Protocol Implementation eXtra Information for Testing (PIXT) proforma specification for the network; English version ETS 300138-6:1997 |