Active Reliable Multicast
To appear in
Stephen J. Garland, and
David L. Tennenhouse
This paper presents a novel loss recovery scheme, Active Reliable Multicast
(ARM), for large-scale reliable multicast. ARM is ``active'' in that routers
in the multicast tree play an active role in loss recovery. Additionally, ARM
utilizes soft-state storage within the network to improve performance and
scalability. In the upstream direction, routers suppress duplicate NACKs from
multiple receivers to control the implosion problem. By suppressing duplicate
NACKs, ARM also lessens the traffic that propagates back through the network.
In the downstream direction, routers limit the delivery of repair packets to
receivers experiencing loss, thereby reducing network bandwidth consumption.
Finally, to reduce wide-area recovery latency and to distribute the
retransmission load, routers cache multicast data on a ``best-effort'' basis.
ARM is flexible and robust in that it does not require all nodes to be active,
nor does it require any specific router or receiver to perform loss recovery.
Analysis and simulation results show that ARM yields significant benefits even
when less than half the routers within the multicast tree can perform ARM