DSR The Dynamic Source Routing Protocol

1. DSRThe Dynamic Source Routing Protocol Students: Mirko Gilioli Mohammed El Allali

2. Introduction DSR is designed for MANETs DSR doesn’t need any network infrastructures Loop free routing No routing information in the intermediate nodes Nodes may easily cache this routing information for future use

3. Assumption for the simulation • All nodes in the MANETs are willing to partecipate fully in the DSR protocol. • The diameter of the MANET will often be small (5 to 10 hops). • The speed with which node moves, is moderate with respect to the packet transmission latency. • Nodes may be able to enable “promiscuous” receive mode on their wireless network interface. • DSR operate with uni-directional link. • Each node selects a single IP address.

4. DSR Mechanisms • Route discovery • Route maintenance • Mechanisms “on-demand” • No periodic routing advertisement • No link status sensing • No neighbor detection packets • Routes caching

5. Basic DSR Route Discovery • Before… • Route discovery starts…

6. Basic DSR Route Discovery • Route reply message • Piggyback • Exponential back-off • The node must limit the Route Discovery’s rate until a route reply message is received • The additional data packet sent over the limit should be buffered

7. Basic DSR Route Maintenance • Each node transmitting the packet is responsible for confirming that the packet has been received by next hop. • Acknowledgement • By lower layer protocol MAC • By DSR-specific software ack • Route errore message

8. Additional Route Discovery features • Caching overheard routing information • In presence of uni-directional link • In presence of bi-directional link

9. Additional Route Discovery features • Replying to Route Request using cached routes • The intermediate node must verify that the resulting route being returned contains no duplicate nodes listed in the route record

10. Additional Route Discovery features • Preventing Route Reply storms • Many Route Reply message could be send to A from the A’s neighbors • To avoid a possible local congestion, each nodes must wait a variable period before sending the reply. • Delay period d = H(h - 1 + r) • Each node network interfaces works into “promiscuous” receive mode.

11. Additional Route Discovery features • Route request Hop limits • “Nonpropagating” Route Request • “Propagating” Route Request • “Expanding ring”

12. Support for Heterogeneous networks & mobile IP Heteregenous network : Different kind of devices with different interfaces. Possibly , multiple interfaces( short range & long range)

13. Support for Heterogeneous networks & mobile IP Heteregenous network : Different kind of devices with different interfaces. Possibly , multiple interfaces( short range & long range)

14. Source routeA/1→B/1→C/4→D/1 Reverse routeD/1→C/4→B/2→A/1

15. Internet Interconnection and MIP

16. DSR evaluation • Simulation • To analyse the behavior and performance of DSR. • To Compare with other routing protocols • Set Up: • Ad hoc of 50 mobiles nodes • 15 minutes ( 900 seconds) simulation time. • CBR data traffic • 20 mobile nodes traffic sources; 4 packets/sec. • Random waypoint mobility model ( pause time)

17. Results

18. Results

19. Results

20. Results

21. Conclusion • Excellent performance for routing in multi-hop ad hoc. • Very low routing overhead. • Able to deliver almost all originated data packets, even with rapid motion of all nodes.