DSR The Dynamic Source Routing Protocol Students: Mirko Gilioli Mohammed El Allali

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

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.

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

Basic DSR Route Discovery Before… Route discovery starts…

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

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 lower layer protocol MAC By DSR-specific software ack By DSR-specific software ack Route errore message

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

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

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

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

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

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

Source route A/1→B/1→C/4→D/1 Reverse route D/1→C/4→B/2→A/1

Internet Interconnection and MIP

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

Results

Results

Results

Results

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.