We address the problem of message ordering for reliable multicast communication. End-to-end multicast ordering is useful for ensuring the collective integrity and consistency of distributed operations. It is applicable for distributed multiparty collaboration or other multipoint applications, where the ordered reception of messages at all hosts is critical. Existing reliable multicast protocols largely lack support for ordering. Our novel mechanism can be added to existing reliable multicast services at low cost by performing cascaded total ordering of messages among on-tree hosts en route from senders to receivers. The protocol operates directly on a given end-to-end multicast tree, contrasting other tree-based approaches requiring a separate propagation graph to be built to compute ordering information. For better load distribution, resilience, and ordered subcasting of messages within multicast groups, sequencer nodes are elected dynamically based on address extensions to hosts in ...
Hans-Peter Dommel, J. J. Garcia-Luna-Aceves