Written by kashif

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