Question 18/XVIII - ISDN connection types

Considering

(a) the Recommendations on ISDN connection types and their corresponding
reference configurations;

(b) that the required range of services to be supported by an ISDN is
likely to be expanded in the future and that the number of connection
types required to support these services should be limited;

(c) that continuous advances in technology may make it desirable to
modify some values of attributes of ISDN connection types;

(d) the need to develop reference configurations to describe network
performance of ISDN connection types;

(e) that further development of the connection type concept will be
required to take account of the needs of interconnection with private
networks, broadband capabilities (including broadcast and multipoint
connection, mobile services, intelligent network services and universal
personal telecommunications services);

the following should be studied:

1. What modifications, if any, are required to the connection types
specified in Recommendation I.340?

2. What additional ISDN connection types should be identified?

3. What enhancements are needed to the definition of ISDN connection
types to cater for the evolution of ISDN (including new transfer modes)
and implementation of change in service during progress of a call?

4. How should ISDN connection types be detailed to cater for non-uniform
connections?

5. How should reference configurations for ISDN connection types be
further developed taking into account the concepts contained in
Recommendation I.340, e.g.:

1.in what level of detail should reference configurations address the
topological considerations and other functionally related aspects of
connections in order to provide a good basis for the development of
HRXs;

2.are the number of ISCs and other network nodes reduced in the case of
satellite based connections and, if so, in what manner and with what
impact;

3.for satellites involved in the distribution of multipoint narrow and
broadband services, what are appropriate new reference configurations
and HRXs and how can existing ones be modified to take account of these
capabilities?

Note - In the studies for developing HRXs for particular network
performance parameters, it will be necessary to ensure that these HRXs
are derived from and consistent with the reference configurations
available for the relevant connection types and which refer to the
network performance parameters.