Question 16/XVIII - ISDN architecture and functional principles,
characterization methods and reference configurations (including user-
network interfaces)

Considering

(a) existing Recommendations on network functional principles,
architectures, reference configurations, models and methodologies;

(b) that there is a need to develop further and/or enhanced
Recommendations on these aspects taking account of new network
capabilities and services;

the following should be studied:

1. What enhancements if any need to be made to the characterization
methods of ISDN services and network capabilities?

2. What new and enhanced Recommendations are required to take account of
the architectural and functional modelling aspects of:

2.1further capabilities of the (64 kbit/s) ISDN;

2.2network management and control functions;

2.3 functional interfacing with private networks (including mixed
public/private network applications);

2.4functional integration of mobile services networks with the ISDN;

2.5intelligent networks;

2.6universal personal telecommunications;

2.7B-ISDN (including broadcast multipoint and multimedia applications?

3. What new and enhanced reference configurations need to be developed:

-for new access arrangements;

-for the allocation of performance objectives to accommodate mobile
access to the ISDN;

-for network interworking;

-to cater for BB-ISDN?

4. What extensions to the concept of digital sections are required to
cater for new network capabilities?

Note 1 - With reference to study item 2.3 the purpose of the study is to
establish an overall network reference model to cover interactions of
mixed public/private networks in order to:

i) enable consistent service descriptions to be developed; and

ii) provide guidance for the development of protocols.

Note 2 - An architectural reference model and associated guidelines are
needed which provide a uniform framework for:

-identifying network functions for service call control;

-grouping network functions to create functional entities;

-identification of basic physical network entities/resources;

-mapping functional entities onto physical entities/resources;

-showing the relationship between network functions to support
telecommunications services and those required for network management
and operations.