This Recommendation defines the operation of the Digital Subscriber Signalling System No. 2 (DSS 2) for the handling of the Connection characteristics negotiation during Call/Connection establishment phase, that may be supported, as a network option, 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 Connection characteristics negotiation capability defined in this Recommendation enables in particular the negotiation of cell rate traffic parameters using an alternative set of values given in an alternative ATM traffic descriptor information element, or negotiation of cell rate traffic parameters by using a minimum acceptable traffic descriptor information element containing minimum acceptable traffic parameter values. This revised edition extends the scope of ATM traffic parameter negotiation capability in Q.2962 (1996) to include the possible negotiation of SCR and MBS parameters within a range down to minimum acceptable SCR and MBS parameters values.