A Membership Management Protocol for Mobile P2P Networks
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Transcript of A Membership Management Protocol for Mobile P2P Networks
A Membership Management Protocol for Mobile P2P
NetworksMohamed Karim SBAI, Emna SALHI, Chadi BARAKAT
Mobile Ad hoc Networks Spontaneous multi-hop wireless networks
end-to-end communication ad hoc
routing protocols Without any established infrastructure
Nodes play symmetric roles No
dedicated nodes. Using wireless channel Limited and shared resources Mobility Network splits
P2P Networks Peer-to-peer services (as known in the
Internet)
Without dedicated devices (servers)
Peers play symmetric roles Both
clients and servers. Can use fixed servers to track the
members of the overlay The mechanism are not adapted to
mobile constrained environments
Membership Management Protocol for mobile P2P networks
Objective: Maintaining an up-to-date list of the peers
interested in the P2P service.
Challenges:- Minimum cost on the underlying network.
- Ensuring the continuity of the service.- Having a good level of the freshness of information.
A membership management protocol for P2P services run over MANET ?
Client / Server Flooding-based method Multicast-based method P2P
Adaptive and optimal P2P method ?
Membership Management Protocol
Our solution:
A fully distributed protocol for constructing and maintaining minimum spanning trees of interested peers.
robust adaptive network friendly decentralized
Algorithms:
1. Joining the membership tree2. Leaving the membership tree3. Adapting the membership tree to mobility of nodes4. Network split awareness
Joining the membership tree
Looking for the nearest peer a controlled-scope flooding method
Connecting to the nearest peer and getting the current tree from it
Dissemination of the new arrival information on the tree
Changing some connections of the tree considering the cut property of a minimum spanning tree.
Adapting the tree to mobility of nodes Two peers that are neighbors in the tree can get
closer the tree is still optimal. Two peers that are not neighbors in the
spanning tree get farther from each other the cost of the tree does not change and no better decision can be made.
Two peers that are neighbors in the spanning tree get farther from each other. The cost of the tree increases there might exist a better tree. CASE 1
Two peers that are not neighbors in the spanning tree get closer to each other It might be another tree with smaller weight. CASE 2
Adapting the tree to mobility of nodes
CASE I = CASE 2 If one of the peers get nearer to another peer in the tree. Else, no optimization can be made.
CASE 2 : Using the cycle property of a minimum
spanning tree to elect the logical link to cut.
Leaving the membership tree
The child of the leaving peer having the highest identifier connects to its parent and becomes the parent for the remaining children. A new spanning tree
The optimal is reached by having the peers apply the normal approaching adaptation procedure.
Network split awareness
Tagging network nodes that are not interested in the same service.
Tracks continuously the appearance of non tagged nodes in its neighborhood.
A new node not tagged and not belonging to the same membership tree is a good candidate to be asked whether it belongs to the same service but comes from another cluster.
Executing a join procedure in case the node is a peer.
Packet format
Performance evaluation Performance metrics:
Real cost: number of hops message Cost corrected by freshness of information
NS-2 Simulations scenario :
50 nodes / Random way point (2ms, 30s) / OLSR routing protocol exponentiel distribution of ON and OFF times of peers
Performance evaluation
Client/server method
Performance evaluation
Performance evaluation
Performance evaluation
Performance evaluation
Performance evaluation
Performance evaluation
Thank You