ETSI EN 302 092-4 Broadband Integrated Services Digital Network (B-ISDN) and Broadband Private Integrated Services Network (B-PISN); Digital Subscriber Signalling System No. two (DSS2) and Broadband QSIG (B-QSIG) protocols; Call control specification in separated call and bearer control environment; Part 4: Abstract

standard by European Telecommunications Standards Institute, 09/01/2000