IGMP is a protocol for managing and controlling multicast of data streams to a plurality of end users connected to a telecommunications network through an access system. A novel implementation of IGMP for multicasting data streams in an xDSL access network system is disclosed. DSLAM (Digital Subscriber Line Asynchronous Multiplexer) or ASAM (ATM Subscriber Access Multiplexer) is used in the access network system and interfaces between the telecommunications network and the plurality of end users. IGMP signals are terminated at LT (Line Termination). A better scalability of the access system can be achieved, resulting in increased numbers of end users.