This Recommendation defines the operation of the Digital Subscriber Signalling System Number 2 (DSS 2) for Generic Functional Protocol core functions 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 Generic Functional Protocol core functions defined in this Recommendation provide a means of exchanging ROSE components on behalf of signalling application in peer entities. These signalling applications may either be for the support of supplementary services or provide protocol support for the other features (such as Look Ahead, Status request, Local/remote interrogation), in association with existing calls and bearers (bearer related signalling), or independently of existing bearers (connection-oriented or connectionless bearer independent signalling).