An efficient multicast algorithm for ABR service in ATM networks

We propose a new efficient rate control algorithm for a multicast available bit rate (ABR) service. In the proposed scheme, among the received backward resource management (RM) cells with the same sequence number, each branch point passes only one backward RM cell experiencing the longest round trip time (RTT) from itself to its destinations. The source therefore gets exactly one backward RM cell corresponding to every forward RM cell it generates. The proposed multicast algorithm ensures that the congestion information about any branch can be relayed to the root within the longest RTT in the multicast tree, regardless of the number of branch points which it passes through. Moreover, since the branch point preserves the latest congestion information carried by the previous backward RM cell for each branch, consolidation noise can be avoided by exploiting these information for those branches, whose backward RM cells have not been received.