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