scope:

The present document specifies the signalling protocol for ATM Traffic Descriptor modification for the Broadband-Integrated Services Digital Network (B-ISDN) at the T_B reference point or coincident S_B and T_B reference point (as defined in ITU-T Recommendation I.413 [1]) by means of the Digital Subscriber Signalling System No. 2 (DSS 2). The present document extends the Peak Cell Rate (PCR) parameters modification capability specified in EN 301 003-1 to include the modification of the Sustainable Cell Rate (SCR) and the Maximum Burst Size (MBS) parameters

n addition, the present document specifies the protocol requirements at the T_B reference point where the service is provided to the user via a private B-ISDN.

The capability described in the present document enables the connection owner to modify the ATM Traffic Descriptor for call/connections that have already been established.

ATM Traffic Descriptor modification is applicable to all connection oriented telecommunication services that are based on single point-to-point calls/connections, however, modification is not applicable to emulated N-ISDN services. The peak cell rate modification for point to multipoint calls/connections is outside the scope of the present document

The present document is applicable to equipment, supporting ATM Traffic Descriptor modification, to be attached at either side of a T_B reference point or coincident S_B and T_B reference point when used as an access to the public B-ISDN.

Further ENs (or further parts of the present document) provide the method of testing and detailed application specific requirements to determine conformance to the present document.

The provision of this service requires the support of the protocol for the basic point-to-point call/bearer connections as defined in EN 300 443-1 [5].