AODV: Path Setup
n eventually, RREQ will reach a node with route to destination
problem: what if route is old?
solution: source includes destination sequence number in RREQ to
indicate desired “freshness”
if node’s destination sequence number is less than the one in RREQ, keep
forwarding RREQ to neighbors
n if acceptable route information, unicast RREP back to neighbor who
sent out RREQ, which follows reverse path back to source, setting up
route along the path
n nodes that are not on reverse path will timeout and delete temporary
information (timeout interval chosen appropriately, make sure that
there is enough time for route to be discovered….)
n if node receives multiple RREP, propagate first, and additional ones
only if they indicate better path (using DSDV criteria):
greater destination sequence number (“fresher” route)
same destination sequence number with smaller hopcount