Abstract: A method for performing end-to-end “tree-based ordered multicasting” (TOM) which ensures collective integrity and consistency of distributed operations, and which is applicable to distributed multiparty collaboration and other multipoint applications. The TOM protocol performs cascaded total ordering of messages among on-tree hosts en route from senders to receivers, and does not require the building of a separate propagation graph to compute ordering information. TOM elects sequencer nodes dynamically based on address extensions of the multicast tree. Message ordering is performed by multicasting a message from each source node to receivers, unicasting a control message from a source node across a primary node to an ordering node for the designated multicast group or transmission in the tree, determining a binding sequence number for the message and a multicast to the receiver group, and delivering messages at end hosts according to the agreed-upon sequence numbers.

Abstract: A protocol to coordinate multipoint groupwork in the IP-multicast framework. Called Aggregated Coordination Protocol (ACP), the protocol operates on a shared multicast tree, benefiting from the underlying tree structure to store and forward coordination primitives between hosts in different multicast groups on the tree. ACP coordinates distributed activities via message passing, and manifests control by ephemeral permissions rather than actual locks, allowing control over continuous media flows as well as discrete data. The protocol supports Internet-wide coordination for large and highly interactive groupwork, relying on transmission of coordination directives between group members across a shared end-to-end multicast tree.

Abstract: A method for performing end-to-end “tree-based ordered multicasting” (TOM) which ensures collective integrity and consistency of distributed operations, and which is applicable to distributed multiparty collaboration and other multipoint applications. The TOM protocol performs cascaded total ordering of messages among on-tree hosts en route from senders to receivers, and does not require the building of a separate propagation graph to compute ordering information. TOM elects sequencer nodes dynamically based on address extensions of the multicast tree. Message ordering is performed by multicasting a message from each source node to receivers, unicasting a control message from a source node across a primary node to an ordering node for the designated multicast group or transmission in the tree, determining a binding sequence number for the message and a multicast to the receiver group, and delivering messages at end hosts according to the agreed-upon sequence numbers.

Abstract: A protocol to coordinate multipoint groupwork in the IP-multicast framework. Called Aggregated Coordination Protocol (ACP), the protocol operates on a shared multicast tree, benefiting from the underlying tree structure to store and forward coordination primitives between hosts in different multicast groups on the tree. ACP coordinates distributed activities via message passing, and manifests control by ephemeral permissions rather than actual locks, allowing control over continuous media flows as well as discrete data. The protocol supports Internet-wide coordination for large and highly interactive groupwork, relying on transmission of coordination directives between group members across a shared end-to-end multicast tree.