Question 21/III - Charging and accounting principles to be applied to
the services offered by an Integrated Services Digital Network (ISDN)
(continuation of Question 22/III studied in 1985-1988)

(This Question must be studied in liaison with Study Groups I, II, VII,
XI and XVIII, as necessary.)

Reasons for the study

Considering

(a) that additional progress has been made in the field of services
definition and of technical specifications which are the subject of
various Recommendations in the I-, Q-, E-, M-, V- and X-Series;

(b) that during the 1989-1992 study period countries:

- will be implementing pure ISDN for some services, and/or

-providing services via a combination of existing network(s) and ISDN;

(c) that general charging and accounting principles are established for
certain services and are the subject of D-Series Recommendations, that
other principles have to be defined and established for services which
will be implemented in a next step, and that there is a requirement for
harmonization between existing and new Recommendations;

(d) that existing Recommendations relating to ISDN charging and
accounting principles will need to be updated as experience with
services implementation is gained,

What charging and accounting principles are appropriate to guide the
development and implementation of services to be supported by ISDNs?

This study will establish:

-general charging and accounting principles for bearer services (in
demand, reserved and permanent modes);

- charging and accounting principles for teleservices;

- charging and accounting principles for supplementary services;1

- charging and accounting principles for services in packet-mode;

-principles regarding the establishment and exchange of international
accounts taking into account the possibilities provided by the
signalling system specific to ISDN (Signalling System No. 7).2,3

- - - - - - - - - - - - - - -
1 Giving priority to services that will be implemented during the
current Plenary period.

2 Introducing, as necessary, appropriate modification to the provisions
of
Recommendation D.170.

3 In the following cases, the settlement of accounts between
administrations
may be based on additional information exchanged over the signalling
system:
a) charging and accounting data, generated at a location other than the
billing point, may be exchanged between administrations together with
identification of the call involved and of the administration
originating the data;

b) charging authorization at a location other than the billing point,
e.g., for reverse charged calls and transferred charging, requires the
exchange of signalling information;

c) in case of transit switched calls, the terminating administration may
receive a marking per call which identifies the originating
administration.