This Standard specifies the signalling protocol for the support of the Path Replacement additional network feature (ANF-PR) at the Q reference point between Private Integrated services Network eXchanges (PINXs) connected together within a Private Integrated Services Network (PISN).
ANF-PR is a feature which applies to an established call, allowing that call’s connection between PINXs to be replaced by a new connection.
The Q reference point is defined in ECMA-133.
Service specifications are produced in three stages and according to the method specified in ETS 300 387. This Standard contains the stage 3 specification for the Q reference point and satisfies the requirements identified by the stage 1 and stage 2 specifications in ECMA-175.
The signalling protocol for ANF-PR operates on top of the signalling protocol for basic circuit switched call control, as specified in ECMA-143, and uses certain aspects of the generic procedures for the control of supplementary services specified in ECMA-165.
This Standard also specifies additional signalling protocol requirements for the support of interactions at the Q reference point between ANF-PR and other supplementary services and ANFs.
This Standard is applicable to PINXs which can interconnect to form a PISN.
The protocol defined in this Standard forms part of the PSS1 protocol (informally known as QSIG).