Figure 3.1 Xcast packet delivery [10]
In general, the process that a router will do upon receiving an Xcast packet is as follows:-
• Determine the next hop for each set of destinations by performing a route table
lookup.
• Based on the next hop, the destinations will be divided into groups.
• Create a number of packets according to the number of groups from the previous
step.
• Send each packet to its next hop with the modified packet header.
• If there is one destination for any of the next hops, this packet can be sent unicastlly
by using the underlying routing protocol.
Compared to traditional multicast protocols, Xcast has the following advantages:
J Because it is a stateless protocol, routers need not keep any state information about
the multicast group members.
J No need for multicast routing protocol, Xcast achieved the multicast concepts
explicitly and the path is taken from the underlying unicast routing protocol.
J No single point of failure happens, as there is not core node required in Xcast.
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