Information technology -- Telecommunications and information exchange between systems -- Private Integrated Services Network -- Inter-exchange signalling protocol -- Private User Mobility (PUM) -- Call handling additional network features

ISO/IEC 17878:2003 specifies the signalling protocol for the support of the Private User Mobility call handling additional network features (ANF-PUMI and ANF-PUMO) at the Q reference point between Private Integrated services Network eXchanges (PINX) connected together within a Private Integrated Services Network (PISN).

ANF-PUMI is a feature that directs incoming calls to a PUM user within the PISN regardless of the PUM user's geographical location within the PISN, provided that the PUM user's location is known.

ANF-PUMO permits the PISN to process call requests from a PUM user at the home location, if required.

The Q reference point is defined in ISO/IEC 11579-1.

Service specifications are produced in three stages and according to the method specified in ITU-T Rec. I.130. ISO/IEC 17878:2003 contains the stage 3 specification for the Q reference point and satisfies the requirements identified by the stage 1 and stage 2 specifications in ISO/IEC 17877.

The signalling protocol for ANF-PUMI and ANF-PUMO operates on top of the signalling protocol for basic circuit switched call control, as specified in ISO/IEC 11572, and uses certain aspects of the generic procedures for the contr