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2009/2010

Peer To Peer

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Summary

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Conclusion 6

Introduction

Architecture

Characteristic of P2P

The eMule application

P2P File-sharing Protocols

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Introduction

Direct system exchange of resources between linked peers in network

The most used in the world

Basically different from the Client-server architecture

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Architecture of P2P

Peer to peer is a type of network infrastructure where each computer is both server

and client. In this case, the computers connected to the network share their resources .

• Distributed Architecture • Decentralized architecture

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P2P Network administration

In a typical peer-to-peer, there is no administrator .So,

each user manages his own post. On the other hand all users

can share their resources as they wish. If we consider one of

the posts as a server, it is intended to share resources, if not it

consumes resources from other posts

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P2P Network security

For the P2P there are problems that are related to the system itself and

other software.

The files on these networks in addition to their potentially illegal

distribution come from unverifiable sources and can contain all kinds of additives:

spyware, viruses and other .. Anyway download any file whatever it is, should

lead to a systematic virus verification.

Also put passwords to the data, even if they are not in shared directories.

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Benefits of P2P

A reduced cost

Simplicity of implementation and use

Robust network,

Self-organization

Dynamism

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Disadvantages of P2P :

Limited change

This system is not centralized at all, which makes it very difficult to administer

Security is less easy to achieve

The network maintenance is difficult.

Trafficking is most important and searching files take much longer

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P2P software

Shareaza client is a peer-to-

peer for Windows that will

allow you to download files

of any type on several

popular P2P networks.

It has emerged as a software

exchange and sharing

essential

Is based on the

distributed network

Fasttrack

developed in Java by the

creators of Winamp based on

the distributed network

Gnutella.

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The eMule application

eMule is a P2P file sharing network

• Based on an extended eDonkey protocol

• Uses both TCP and UDP

• Client Server architecture

Definition :

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The eMule Network :

The eMule application

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P2P File-sharing Protocols

1- Connection establishment :

High ID login sequence Rejection session

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This scenario assumes that the client has a requested file list

The client sends his files The server replies with status

information The client asks for sources for

his files The server replies with his

available sources

P2P File-sharing Protocols

2- Connection startup :

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P2P File-sharing Protocols

3- File search :

• A search request is sent to the server which is then answered

by a search result

• The user chooses to download one or more files, the client then

requests sources for the chosen files and the server replies with a

list of sources for each of the requested files.

• An optional server status message

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P2P File-sharing Protocols

4- Callback mechanism:

1- A can send the server a callback request to ask B to call him back.

2- The server, which already has an open TCP connection to B, sends B a

callback requested message, providing him with A’s IP and port.

3- B can then connect to A and send him the file without further overhead on

the server.

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UDP communication

P2P File-sharing Protocols

UDP is used for:

◦ periodic status checks

◦ File search enhancement

◦ Source search enhancement

UDP is optional

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UDP communication

P2P File-sharing Protocols

UDP is used for verifying A’s position in B’s upload queue

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Conclusion

The importance and the the future of P2P is to provide a role in network security and continuity.

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Thank you for your attention