ITU-T I.250 PDF

General

Recommendation I.210 describes the principles for defining telecommunication services supported by an ISDN including the concept of bearer services, teleservices and supplementary services. It also provides the means for the definition and description of such services.

The purpose of this Recommendation is to define a recommended set of supplementary services to be used in association with basic bearer services and with basic teleservices. These definitions form the basis for detailed descriptions as given in Recommendations I.251 to I.257, which are used to define the network capabilities required.

Supplementary services are described by prose definitions and descriptions and by dynamic descriptions following the description method given in Recommendation I.130. The application for supplementary services of the attribute technique described in Recommendation I.140 is for further study.

Note - Alignment and interworking between user facilities as defined in Recommendations X.2 and X.301 for the provision of data transmission services and the supplementary services in the I.250-Series and interworking in the I.500-Series of Recommendations require further study.