AD HOC ON DEMAND DISTANCE VECTOR

AODV tries to address the problem of the variable sized header of DSR by maintain a reduced routing table suitable for manets

LIMIT THE ROUTING PROBLEMS OF MANETS

In order to avoid limit the header lenght problem, 2 routing tables are used:

• inverse path routing table that is used to route the route reply packets, the records on this table are removed after a timeout

SOURCE	DESTINATION	DISTANCE FROM THE SOURCE
S	D	1

• direct path routing table that is used to route the actual traffic to the destination this table does the heavy lifting

	DESTINATION	NEXT HOP	DISTANCE FROM THE DESTINATION
S	D	F	3

flowchart TD
a[the source sends a packet \n with source and destination in flooding mode]
b[nodes that recive the packets \n start the creation of a routing table of the inverse paths]
c[the destination recives the packet \n and send a route reply packet to the source \n the unicast transmision does not contain the full path \n but exploits the routing tables]
d[nodes that recive the packets \n start the creation of a routing table of the direct paths]
a --> b
b --> b
b --> c
c --> d

ROUTE ERROR

In the route error scenario the node that detects the route error situation informs the other nodes like in DSR and they update their routing table, the message is broadcast to the neighbors route error to inform them

LINK FAILURE DETECTION

Extension that force all nodes to send hello messages to the neighbors in order to discover broken routing table lines

AVOID THE FLOODING PROPAGATION

In order to avoid the excessive flooding if an intermediate node has already the route information can respond with a route reply, this generate some loop problems

USING DSN TO AVOID LOOPS

So in order to avoid loops, an integer value is introduced (DSN) that is incremented with each propagation of a route request packet, if the