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Diffstat (limited to 'ace/RMCast/README')
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diff --git a/ace/RMCast/README b/ace/RMCast/README new file mode 100644 index 00000000000..d8cfbc040c7 --- /dev/null +++ b/ace/RMCast/README @@ -0,0 +1,22 @@ +RMCast is a reliable source-ordered multicast protocol implementation +for message-oriented multi-sender group communication built on top of +IPv4 multicast. It uses sequence numbers for re-ordering, duplicate +suppression and loss detection. Negative acknowledgments (NAK) with +retransmissions are used to recover from losses. + +One new and interesting idea implemented in this protocol is history +transmission (dubbed negative retransmission). In a nutshell, each +sender, along with normal payload, transmits a list of other sender's +IDs along with sequence numbers of last messages received from those +senders by this member. This, in some sense, builds a pyramid of +information: each subsequent message carries some information for a +number of previous messages (from other senders). This helps other +receivers detect losses. + +The protocol does not track group membership. Messages are retained +for retransmission for a predefined amount of time. The "last message +or lost message" dilemma is solved by periodic history transmissions +in cases when there is no useful traffic (idle network). + +-- +Boris Kolpackov <boris@kolpackov.net> |