1. Evaluation of Ad hoc Routing Protocols under a Peer-to-Peer Application Authors: Leonardo Barbosa Isabela Siqueira Antonio A. Loureiro Federal University of Minas Gerais – Brazil Computer Science Department - http://www.dcc.ufmg.brhttp://www.dcc.ufmg.br

2. Summary Introduction Motivation P2P implemented protocol Simulation and results Conclusion Questions

3. What is P2P? Distributed paradigm Dynamic topology Nodes have equivalent funcionalities and provision capacities (peers) Peers play the role of servers and clients simultaneously (servents)

4. What are P2P applications? P2P sharing systems Able to share Hard disk space Files CPU Phenomena in the Internet Examples: Gnutella, Freenet, Napster, ICQ

5. P2P Applications and MANETs P2P paradigm is the basis for both MANETs and P2P applications Central units are non-existent in both environments Their nodes are clients and servers at the same time Self-organizing networks Responsible for routing queries in a distributed environment

6. Faithfulness to the Model P2P applications Usually built over a network based on the Client/Server model Clients of foreign servers Neighbors might be geographically many hops apart MANETs: Implement their own communication mechanism Only communicate with servents Peers are only a single-hop away from their neighbors

7. Motivation Similarities between the systems Scarcity of work in which both systems coexist Could P2P applications become “killer applications” in MANETs?

8. By means of this... Direction and Speed Out of Range Ad hoc Connection Transmission Range MANET

9. ... and this... Router Peer Connection among P2P application nodes Connection among routers and peers Connection among routers P2P Application Network

10. ... this was built! Ad hoc node P2P application node Connection among P2P application nodes Connection among application and MANET nodes P2P Application Network over a MANET

11. P2P Implemented Protocol Based on Gnutella Joining the network Transmission of a broadcast message searching for neighbors BROADCAST-SEND Achieved peers respond BROADCAST-REPLY Neighbors election

12. P2P Implemented Protocol Searching Query transmissions to neighbor peers QUERY-SEND Process goes on until the information is found or dropped In case it is found, the servent that owns the file wanted responds to the “query-source” peer QUERY-REPLY Transferring files Establishment of an end-to-end communication Fragmentation and transference of the information

13. P2P Implemented Protocol Controlled flooding Each peer has a cache to avoid a request being handled twice P2P header includes TTL Connectivity control PING and PONG messages

14. Simulation 40 mobile nodes, 12 executing an instance of the P2P application Grid: 200m x 200m MAC protocol: IEEE 802.11 Energy consumption: 0.3W (Tx), 0.2W (Rx) Each scenario was simulated 33 times Simulation time: 300 s

15. Simulation Evaluated protocols: Dynamic Source Routing Protocol (DSR) Destination-Sequenced Distance-Vector Routing (DSDV) Ad Hoc On Demand Distance-Vector (AODV)

16. Analysis Methods Workload Amount of requests per peer Size of shared files Mobility Pause time Speed Network Density Number of nodes Transmission range Amount of Peers

17. Workload DSDV presented the most overhead and stability when the number of queries were augmented (2000 packets on average) The behavior of the other protocols were similar Queries (amount) Overhead (pkts)

18. Mobility Latency as function of speed increased exponentially when DSR protocol was used (climbed to 10x more) All protocols provided more information unavailability and worse P2P connectivity in low levels of mobility Latency (s) Speed (m/s)

19. Network Density The curves of the delivery ratio as function of the amount of nodes behaved equivalently for the three protocols The curves climbed rapidly when the network was little densed Above 20 nodes delivery ratio was between 60 and 70% Nodes (amount) Delivery Ratio (%)

20. Peers (amount) Peers Hops (number) DSR was the protocol that calculated the worst routes and had the major impact when the number of peers increased There was an increase in the range from 10 to 20 peers

21. Conclusion “There is no silver bullet”, each of the protocols analysed performed well in some scenarios for some metrics while had drawbacks in others It is important to identify accurately characteristics of the P2P application (load, amount of peers etc.) in order to opt for a protocol

22. Questions? Thank you for your attention! Contacts E-mail: {leob,isabela,loureiro}@dcc.ufmg.br Home Page: http://www.dcc.ufmg.br/~leob Research Group Site: http://www.lecom.dcc.ufmg.br/~tbb