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• The destination node must be more than two hops away from the
coordinator. For one or two hops, there is no ambiguity in the route, so
no routing packet is required.
• The last time a packet was sent through the top-most router in a sub-tree,
the destination address was different from the address of the packet
currently being sent.
5. To create a routing packet, the coordinator builds a list of short addresses for
each node in the chain to get to the destination node. The coordinator then
sends the routing packet to the first router node in the chain. This causes
each router in the chain to remember the route for the following data
packet(s). The list does not include the destination short address, since the
last router in the chain will recognize the data packet's final destination
address as the address of one of its own children, and will send the packet on
without any explicit routing information.
A.5 Examples of network operation For the following examples, see Figure A-5-1. Note that IEEE 802.15.4 headers are
variable-length, with some fields omitted depending on the value of the various fields
within the FCF.