This Recommendation defines the operation of the Digital Subscriber Signalling System No. 2 (DSS 2) for the support of the SBR2 and SBR3 ATM transfer capabilities defined in Recommendation I.371 that may be used for basic call and connection control at the TB or at the coincident SB and TB reference point of the user-to-network interface of the Broadband Integrated Services Digital Network (B-ISDN). The additional procedures defined in this Recommendation enable the call requesting user to invoke call/connection establishment between users using a connection for which the Statistical Bit Rate configuration 2 or 3 (SBR2 or SBR3) ATM transfer capability is applied by the network.