Evaluation of Ad hoc Routing Protocols under a Peer-to-Peer Application
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Transcript of Evaluation of Ad hoc Routing Protocols under a Peer-to-Peer Application
Evaluation of Ad hoc Routing Protocols Evaluation of Ad hoc Routing Protocols under a Peer-to-Peer Applicationunder 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.br
SummarySummary
Introduction Motivation P2P implemented protocol Simulation and results Conclusion Questions
What is P2P?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)
What are P2P applications?What are P2P applications?
P2P sharing systems Able to share
Hard disk spaceFilesCPU
Phenomena in the Internet Examples: Gnutella, Freenet, Napster, ICQ
P2P Applications and MANETsP2P 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
Faithfulness to the ModelFaithfulness 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
MotivationMotivation
Similarities between the systems Scarcity of work in which both systems coexist Could P2P applications become “killer
applications” in MANETs?
By means of this...By means of this...
Direction and Speed
Out of Range
Ad hoc Connection
Transmission Range
MANET
... and this ...... and this ...
RouterPeerConnection among P2P application nodesConnection among routers and peersConnection among routers
P2P Application Network
... this was built!... this was built!
Ad hoc node P2P application nodeConnection among P2P application nodesConnection among application and MANET nodes
P2P Application Network over a MANET
P2P Implemented ProtocolP2P 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
P2P Implemented ProtocolP2P 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
P2P Implemented Protocol 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
Simulation 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
Simulation Simulation
Evaluated protocols: Dynamic Source Routing Protocol (DSR) Destination-Sequenced Distance-Vector
Routing (DSDV) Ad Hoc On Demand Distance-Vector (AODV)
Analysis MethodsAnalysis 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
WorkloadWorkload
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)
Overh
ead
(p
kts
)
MobilityMobility
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
Late
ncy (
s)
Speed (m/s)
Network DensityNetwork 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
R
ati
o
(%)
Peers (amount)
PeersPeers
H
op
s (
nu
mb
er)
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
ConclusionConclusion
“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
Questions? Questions?
Thank you for your attention! Contacts
E-mail: {leob,isabela,loureiro}@dcc.ufmg.brHome Page: http://www.dcc.ufmg.br/~leobResearch Group Site:http://www.lecom.dcc.ufmg.br/~tbb