Question 23/III - Tariff and accounting principles to be applied to
permanent and reserved services within the ISDN (continuation of
Question 22/III studied in 1985-1988)

(This Question should be studied in liaison with Study Groups I, II, XI
and XVIII as appropriate.)

Reasons for the study

Considering

(a) that permanent and reserved services will be introduced by
administrations early in the life of the ISDN;

(b) that the existing D-Series Recommendations addressing the lease of
international private telecommunications circuits provide some guidance
for the use of permanent services within the ISDN;

(c) that the existing D-Series Recommendations may not apply well to
reserved services within the ISDN;

(d) that a definition of "Reserved Services" in the ISDN is not yet
finalized,

What charging and accounting principles should be applied to permanent
and reserved services within the ISDN?

The study should include the following:

i) the differentiation between service aspects and network aspects which
may impact on ISDN charging and accounting, particularly in respect of
the use of switched and semi-permanent connections to support reserved
and permanent services;

ii) examination of possible charging options beyond those offered for
existing leased circuit services, as defined in the existing D- Series
Recommendations;

iii) alternative arrangements for the collection of charges (e.g.
billing at either end of the services, both ends, or by an authorized
third party);

iv) appropriate international accounting arrangements for permanent and
reserved services, within the ISDN, particularly as related to the study
of items i), ii) and iii) above.