AODV (Adhoc Ondemand Distance Vector Routing)- MANET REACTIVE ROUTING PROTOCOL

Summary

This video provides an insightful overview of the Ad hoc On-Demand Distance Vector (AODV) routing protocol, a key method used in reactive networking. AODV efficiently establishes routes only when data needs to be transmitted, contrasting with Dynamic Source Routing (DSR) by maintaining routing tables for better bandwidth utilization. The protocol employs sequence numbers and broadcast IDs to ensure route freshness and manage the discovery process. Through a clear example of nodes communicating, the video illustrates how AODV updates routing tables and facilitates data transfer, making it a vital protocol for ad hoc networks.

Takeaways

• 😀 AODV (Ad Hoc On-Demand Distance Vector) is a reactive routing protocol that only initiates route discovery when data needs to be sent.
• 😀 AODV improves upon DSR (Dynamic Source Routing) by storing routing information in tables instead of embedding it in data packets, which enhances bandwidth efficiency.
• 😀 The route discovery process in AODV begins when a node broadcasts a route request (RREQ) packet to find a path to the destination.
• 😀 AODV uses sequence numbers to ensure that routing information is current, preventing outdated data from causing routing loops.
• 😀 The RREQ packet format includes the source address, source sequence number, destination address, destination sequence number, and hop count.
• 😀 Nodes maintain routing tables that track destination addresses, sequence numbers, hop counts, and the lifetime of routes.
• 😀 Each node increases the hop count in RREQ packets to indicate the distance from the source to the destination.
• 😀 When a destination receives an RREQ, it responds with a route reply (RREP) packet that contains the necessary routing information.
• 😀 Intermediate nodes can update their routing tables based on RREQ packets and forward them until they reach the destination.
• 😀 Once a route is established, data packets can be sent without including routing information, as nodes refer to their tables for forwarding decisions.

Q & A

What is AODV and how is it classified?

AODV, or Ad hoc On-Demand Distance Vector, is a reactive routing protocol. It is classified as such because it establishes routes only when needed, specifically when a node wants to send data to another node.

What are the main disadvantages of the DSR protocol?

The main disadvantages of DSR include excessive bandwidth consumption due to the inclusion of the entire routing path in data packets, especially in larger networks, and the possibility of caching multiple routes for a single destination, which can lead to inefficiencies.

How does AODV differ from DSR in terms of route maintenance?

Unlike DSR, which does not use routing tables and includes full paths in data packets, AODV maintains routes in a routing table, allowing for more efficient bandwidth usage as data packets do not carry path information.

What key parameters do nodes in AODV use to maintain routing information?

In AODV, nodes use sequence numbers as timestamps to determine the freshness of routes and a broadcast ID that uniquely identifies each route request packet (RREQ).

What is the structure of a Route Request Packet (RREQ) in AODV?

A Route Request Packet (RREQ) in AODV includes the following fields: source address, source sequence number, destination address, destination sequence number (initially empty if unknown), hop count, and broadcast ID.

Describe the Route Reply Packet (RREP) in AODV.

The Route Reply Packet (RREP) contains the source address, destination address, destination sequence number, hop count, and lifetime, which specifies how long the route can be used.

How does the route discovery process work in AODV?

In AODV, the route discovery process starts when a node broadcasts an RREQ. Each intermediate node that receives the RREQ updates the hop count and rebroadcasts it until it reaches the destination, which then sends back a RREP.

What happens to the routing table when nodes receive RREQ and RREP packets?

When nodes receive RREQ and RREP packets, they update their routing tables with the information contained in these packets, such as the destination, sequence number, and hop count, allowing them to forward future data packets efficiently.

What role do sequence numbers play in AODV?

Sequence numbers in AODV act as timestamps to ensure that nodes are using the most recent routing information, helping to avoid issues such as routing loops and outdated paths.

Can you summarize how AODV improves data transmission compared to DSR?

AODV improves data transmission by maintaining routing information in tables, allowing nodes to forward data packets without including the routing path, thus conserving bandwidth and ensuring efficient use of network resources.