scope:

The present document defines the functional requirements for an "ATM over xDSL" Broadband Access Digital Section (ADS), between the UNI interface at T/S reference point and the Access Network End System at the VB1 reference point, operated over an xDSL connection between an xDSL based Broadband Network Termination and an xDSL based Broadband Line Termination, both these elements being essential constituents of the B-ADS:

a) the definition of B-ADS functional characteristics and protocols should enable proper interworking of the BNT with: a) the Customer Premises Network (B-NT2 or TE) on the customer side;

b) the B-LT and more generally the Access Network End System on the other side, for the provision of ATM connectivity.

At the same time, the specified operational and management requirements will enable proper interworking of the BADS elements with the remaining Access Network elements and with the Service Node, as well as proper B-ADS management.

The document also identifies proper protocols and relevant supporting facilities for the control and management of the Customer Premises Network.