Question 30/I - User indications in the PSTN and the ISDN
(new Question combines parts of Questions 9/II
and 11/II from 1985-1988)

Considering

(a) that subscriber indications in the PSTN and ISDN might take the form
of tones, announcements or visual signals;

(b) that standard indications would help reduce customer errors;

(c) that the tones recommended for telephone service and their
applications appear in the E.180-Series of Recommendations;

(d) that the ISDN may provide the opportunity for more meaningful
international standardization of indications to customers;

(e) that within the ISDN there are many more items of information
transmitted than in the PSTN (information concerning network states,
progress of connection attempts, etc.) and that much of this information
could be useful to the customer under certain circumstances;

(f) that in the ISDN there is a separation of signalling and
communication;

(g) that the most suitable way of presenting information to the user
depends on the terminal being used;

(h) that system response times affect Quality of Service,

the following questions should be answered:

1. What further user indications should be standardized for services
provided through the PSTN and ISDN?

2. What indications should be provided to the user in the ISDN, under
what circumstances, and with what kinds of terminal?

3. What are the best ways to bring progress and status information to
the user, and what opportunities are there for doing so?

4. What indications are required for a passive bus configuration (e.g.
the case where several compatible terminals share one ISDN number)?

5. What are the human factors of system response times affecting
Quality of Service ?