AODV: Path Discovery
n Initiated whenever a source needs to talk to another node
and does not have routing information for that node
n every node maintains two separate counters: node
sequence number and broadcast id (incremented for each
RREQ)
n broadcast RREQ to neighbors, containing these fields
n neighbors either reply with RREP (if they have route to
destination) or pass RREQ on to their neighbors
n drop RREQ if received more than once
n if RREQ is passed on, keep some information to
temporarily establish a reverse path for RREP and
potential establishment of path