Abstract: 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.

Abstract: Whenever a DSLAM or a network node receives a Group Join message, it compares the MAC address of the originating STB to that of previous Join messages with their existing connections. If a match is found, then the DSLAM will initiate a GSQ for the group of the matching previous Join request. If there is not enough resources to satisfy the requirements of Group Join messages, then it may either be ignored, or queued for later processing, once the normal GSQ sequence is complete and resources are available. If the multicast group is no longer needed, the connection to the group is then terminated, as per normal GSQ processing. This frees up bandwidth for any new Join messages. The normal GSQ processing clears the trouble caused by the loss of Leave Message.

Abstract: A fast service restoration for a lost IGMP Leave request. The network node does a comparison to determine if Leave messages are lost in transmission from an end-user system to a supporting network node.