This first part of EN 300 182 specifies the stage three of the Advice of Charge (AOC) supplementary service for the pan-
European Integrated Services Digital Network (ISDN) as provided by European public telecommunications operators at
the T reference point or coincident S and T reference point (as defined in CCITT Recommendation I.411 [1]) by means of
the Digital Subscriber Signalling System No. one (DSS1). Stage three identifies the protocol procedures and switching
functions needed to support a telecommunications service (see CCITT Recommendation I.130 [2]).
In addition, the present document specifies the protocol requirements at the T reference point where the service is
provided to the user via a private ISDN.
The present document does not specify the additional protocol requirements where the service is provided to the user via
a telecommunications network that is not an ISDN.
Three AOC supplementary services exist:
a) Charging information at call set-up time (AOC-S)
The AOC-S supplementary service enables a user to receive information about the charging rates at call set-up
time and also to receive further information during the call if there is a change of charging rates.
b) Charging information during the call (AOC-D)
The AOC-D supplementary service enables a user to receive information on the recorded charges for a call during
the active phase of the call.
c) Charging information at the end of the call (AOC-E)
The AOC-E supplementary service enables a user to receive information on the recorded charges for a call when
the call is terminated.
The AOC supplementary service is applicable to all circuit-switched telecommunication services.
Further parts of the present document specify the method of testing required to identify conformance to the present
document.
The present document is applicable to equipment, supporting the AOC supplementary service, to be attached at either side
of a T (...abbreviated)