ETSI EN 300 141-6
ETSI EN 300 141-6
Integrated Services Digital Network (ISDN); Call Hold (HOLD) supplementary service; Digital Subscriber Signalling System No. one (DSS1) protocol; Part 6: Abstract Test Suite (ATS) and partial Protocol Implementation eXtra Information for Testing (PIXIT) proforma specification for the network
standard published 11/01/1999 by European Telecommunications Standards Institute