The present document specifies the stage three of on-demand connection-oriented release 1 basic telecommunication
services for the pan-European Broadband Integrated Services Digital Network (B-ISDN) as provided at the TB reference
point or coincident SB and TB reference point (as defined in ITU-T Recommendation I.413) by means of the Digital
Subscriber Signalling System No. two (DSS2) protocol. Stage three identifies the protocol procedures and switching
functions needed to support a telecommunications service (see ITU-T Recommendation I.130 [84]).
In addition, the present document specifies the protocol requirements at the TB reference point where the service is
provided to the user via a private B-ISDN.
NOTE 1: Procedures at the TB reference point, to support the access of a private B-ISDN to the public B-ISDN, are
not explicitly identified in the present document, however, some procedures are applicable only at the TB
reference point.
The present document also specifies the particular features required to provide 64 kbit/s based circuit-mode ISDN
services in B-ISDN and to support access interworking between B-ISDN and N-ISDN.
A basic telecommunications service is a fundamental type of service. It forms the basis on which supplementary
services may be added.
NOTE 2: Specific requirements of individual B-ISDN connection-oriented basic telecommunication services are
not covered by the present document.
Further parts of the present document provide the method of testing and detailed application specific requirements to
determine conformance to the present document.
The present document is applicable to equipment supporting connection-oriented basic B-ISDN telecommunication
services, to be attached at either side of a TB reference point or coincident SB and TB reference points when used as an
access to the public B-ISDN.
Clause 1.1
Replace the text of clause1.1 by: