scope:

This European Standard (EN) was produced by ECMA on behalf of its members and those of the European Telecommunications Standards Institute (ETSI). The protocol defined in the present document is the basis for the QSIG protocol for signalling at the Q reference point between Private Integrated services Network eXchanges (PINX). The QSIG protocol is known as "Private integrated Signalling System No. 1" (PSS1) in International Standards. Whilst this particular EN defines signalling for the support of circuit-mode bearer services, other ETSs specify other aspects of the QSIG protocol, e.g. generic procedures for the support of supplementary services, and individual supplementary services. The previous (third) edition of the present document endorsed (with modification) the first edition of ISO/IEC 11572, published in 1994. This edition endorses (with modification) the second edition of ISO/IEC 11572 and two amendments to that International Standard.