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| n |
traditionally,
route maintenance implied in periodic broadcasts of
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state/distance
vector
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– |
as
configuration changes, info will eventually spread through network
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| n |
route
maintenance: send route error packet to sender
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– |
easy
if data link layer provides hop-by-hop acknowledgement (notification
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of
route breaking)
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– |
passive
acknowledgement: if node sends packet to neighbor, it should hear
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neighbor
transmitting packet (symmetric links!)
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– |
active
acknowledgement: force neighbor to ack, use if link has been idle
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for a
while (no data came from next-hope node)
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– |
asymmetric
links: last resort would be end-to-end acks
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| n |
to
send route error packet: node needs route to sender, maybe be
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reversing
route in packet header, maybe by explicit route discovery
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