DSR: Dynamic Source Routing

The Dynamic Source Routing Protocol (DSR) is an efficient routing protocol proposed and designed especially for multi-hop Wireless Mobile Ad-hoc Networks. The protocol automatically discovers (“Route Discovery”) and maintains (“Route Maintenance”) the routing in the network by storing source routes, discovered dynamically only when necessary, thus requiring no administration from the network operator. All nodes in the network participate in the packet forwarding process, acting as routers on an ad-hoc basis. DSR embeds control information to normal packet flow by adding “DSR header” to regular IP packets; the header is modified constantly while the packet is being forwarded. The use of source routing guarantees loop-freeness in the network, and does not require any kind of periodic routing protocol exchanges, thus minimizing the overhead. All nodes cache source routes either when overhearing them or when forwarding the packets, reducing the need for route discoveries. DSR is a reactive protocol and is highly adaptive in the event of movement and node number changes. DSR applies to MANET’s with up to 100 nodes and can cope with a reasonably high rates of node mobility. There is still further study and clarifications to be done, especially in the areas of security and reliability.