Nt1310 Unit 7

AODV has pooled properties of both DSR and DSDV. It uses route discovery process for sustaining route information through the basis of routing table. It is a reactive protocol as it doesn’t need to establish or maintain routes to nodes that are not involved in the communication. AODV handles route discovery process with Route Request (RREQ) messages to broadcast to neighbour nodes. The message floods through the network till the desired destination is reached. Sequence number guarantees the loop freedom. The destination node at once receiving a RREQ unicasts a Route Reply (RREP) back to the source node. Node transmitting a RREP message creates routing table entries for forward route. For route maintenance, nodes send HELLO messages intermittently to neighbour nodes. If any node in the network miss the mark to receive three consecutive HELLO messages from its neighbour, it presumes that link to that particular node is down. A node that perceive a broken link directs a Route Error (RERR) message to any upstream node. At once a node receives a RERR message it will signpost a new source discovery process. The AODV protocol uses sequence numbers to determine the timeliness of each packet and to
Note that the fact that the on-demand approach of the AODV protocol minimizes routing table information. AODV uses traditional routing tables as it is a reactive routing protocol. To determine whether routing information is up-to-date and to prevent routing loops sequence numbers are used. The maintenance of time-based states is a crucial feature of AODV which suggests that a routing entry that isn't recently used is expired. In case of route breakage, the neighbours are notified. The discovery of the route from source to destination relies on query and reply cycles and intermediate nodes store the route information within the type of route table entries along the