General

The Recommendations in the I.200-Series cover the aspects of the telecommunications services supported by ISDNs. They contain the definitions, descriptions and details on the provision of bearer services, teleservices and their associated supplementary services.

In the layout of the I.200-Series of Recommendations the following objectives have been taken into account:

- to achieve a systematic structure which is open to future enhancement;

- to facilitate the requirements of different readers by separating, in specific Recommendations, general service concepts and definitions from Recommendations covering detailed characteristics of individual services;

- to use systematically the service description method given in Recommendation I.130 where, the stage 1, telecommunication services are described in three steps:

1) prose definition and description;

2) static description using attributes;

3) dynamic description using graphic means.