ODMRP (On-Demand Multicast Routing Protocol) is a meshed multicast protocol.
The mesh-based method is responsive protocols that create their routes on demand. In this case for multicast, routes are often created at the request of the source. This one diffuses a message towards the receivers which, when they answer will make it possible to discover the road. This technique is much more robust and resistant to link breaks than that based on tree creation, which makes it much more used in highly mobile MANET networks. Because when a link breaks, which is common in MANET networks, there will probably be another way to deliver the data. Because the fact that the multicast group is composed of a mesh of several redundant routes makes it possible to always have at least one route available.
ODMRP uses the concept of "broadcast area" or "retransmission area", already used in other protocols such as LBM, or GeoGRID. This zone corresponds to the set of nodes that will carry out the retransmission of a message received from a neighbor to another neighbor, that is to say that each of the nodes of this zone participates in the routing and thus composes a road. The protocol will therefore find nodes (member of the multicast group or not), whose role for these nodes, and only these nodes, will be to retransmit packets. edit code
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