The present document specifies the signalling protocol for ATM Traffic Descriptor modification for the
Broadband-Integrated Services Digital Network (B-ISDN) at the TB reference point or coincident SB and TB 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
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.
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 TB reference point or coincident SB and TB 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].