This document proposes using peer-to-peer (P2P) Voice over Internet Protocol (VoIP) communication in large-scale hierarchical mobile ad hoc networks (MANETs). It discusses using a distributed hash table for routing among nodes in a hierarchical topology with cluster heads forming the backbone. The document identifies security and routing efficiency as two important aspects to study for deploying P2P Session Initiation Protocol over MANETs, suggesting approaches like using public key infrastructure and cross-layer design between the P2P and network layers. It recommends using the OMNeT++ simulation tool to implement and test the proposed P2P system.

1. Toward Secure and Efficient Peer-
to-Peer Voice over IP
Communication in Large-scale
Hierarchical Mobile Ad Hoc
Networks
By
Kashif Kashif
Kashif.namal@gmail.com
University of Camerino Italy

2. Mobile Ad Hoc Network
• Formed by Mobile Host which may use Mobile
without using pre exisiting infratucture
• Routes between Nodes may Contain Multiple
Hopsor
• Decrease Dependence on infrastucture
• Use for miltary Operations

3. Layers

4. Peer-to-Peer (P2P) Voice-over-Internet
Protocol (VoIP)
• Protocols are a logical choice
• MANET is also inherently a P2P network
where each node moves from one place to
another independently, joins and leaves the
network as it wishes.

5. Peer-to-Peer (P2P) Voice-over-Internet
Protocol (VoIP)
P2P VoIP uses a distributed hash table (DHT) for
routing among the nodes
• Hierarchical topology consisting of cluster heads
that form the backbone of the MANET
• Cluster head controls a set of ordinary nodes
that form an access MANET network
• MANET uses a broadcast-based MANET physical
routing protocol
• We will use P2P Session Initiation Protocol (P2P-
SIP) defined in RFCs 5694 and 6940,

6. P2P in Military
• We propose to study two important aspects
of deploying P2P-SIP over MANETs
• security and efficiency (routing optimization).

7. Security
• In client/server model, the storage is
distributed in P2P networks
• Need to prevent storage and retrieval attacks
• In Store malicious peer may refuse to store the
data(store data but delete it later or
communication)
• Coordinate attacks with other peers
• P2P-SIP, the SIP protocol requires a
distributed registry service, implemented

8. Security
• Using a lightweight PKI infrastructure: assuming
nodes require some sort of pre-authorization to
join the P2P network. ( X.509 certificates)
• Trust-on-First-Use
• Replication of messages can help ensure correct
routing in the presence of uncooperative or
malicious nodes.
• Replication of data storage can also help deal
with storage and retrieval attacks,

9. Security
• Resistance to storage/retrieval attacks can be
viewed as a case of requiring an agreement in
a completely decentralized manner in the
presence of malicious and uncooperative
nodes, and is known as the Byzantine
Generals problem

10. Routing Optimization
In overlay networks such as P2P-SIP, peers establish a
logical topology at the application layer and communicate
based on this logical topology
• These logical connections are then mapped onto the
underlying physical topology and messages are routed
by the routing mechanism deployed at the network
layer
• If these two layers each independently operate from
one another the Result is poor.
• This is particularly true in MANETs, where the wireless
links that establish the physical topology have limited
bandwidth.

11. Approach to P2P
• We will utilize a cross-layer design
• P2P overlays need to know about the status of the
underlay/physical network (help to reducing the
maintenance o
• MANET algorithms should also be aware of the P2P
overlay in order to maintain the appropriate
connections with relevant neighbouring overlay nodes
overhead).
• Could be achieved either by having the application
layer and network layer exchange information within a
node or by integrating the P2P algorithms

12. Cluster head knowing
There are Multiple MANETs exist, running their
own internal routing protocol. Each MANET
elects a cluster head, and connectivity is
provided among the MANETs by organizing the
clusterheads in a P2P network
• Nodes are free to move and new networks can
join and leave, without the need for a
fixed/centralized network infrastructure.

13. Tool to Implement P2P
OMNeT++
• Component-based C++ simulation library and
framework
• Open Source wired, wireless and mobile
networks, and OverSim
• INET provides the basic protocols and
capabilities to simulate MANETs