The present invention addresses scalability and end-to-end reliability in overlay multicast networks. A simple end-system multicast architecture that is both scalable in throughput and reliable in an end-to-end way is used. In this architecture, the transfers between nodes use TCP with backpressure mechanisms to provide data packet transfers between intermediate nodes having finite-size forwarding buffers. There is also a finite-size backup buffer in each node to store copies of packets which are copied out from the receiver window to the forwarding buffers. These backup buffers are used when TCP connections are re-established to supply copies of data packets for the children nodes after their parent node fails, maintaining a complete sequence of data packets to all nodes within the multicast overlay network. The architecture provides end-to-end reliability, tolerates multiple simultaneous node failures and provides positive throughput for any group size and any buffer size.