ETSI EG 201 066-1 Integrated Services Digital Network (ISDN); Digital Subscriber Signalling System No. one (DSS1) protocol; Application of the Bearer Capability (BC), High Layer Compatibility (HLC) and Low Layer Compatibility (LLC) information elements; Part 1: Test Suite Structure and Test Purposes (TSS&TP) specific

standard by European Telecommunications Standards Institute, 10/01/1997