Introduction to Peer-To-Peer Networks

Author : Pooya Sagharchi Ha November 28, 2014

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Agenda • Computer Network Architecture

• Client-Server • Peer-To-Peer

• Intro Client-Server • Definition • Architecture • Limitation

• Intro Peer-To-Peer • Definition • Architecture • Benefits and Weakness

• Peer-To-Peer Application • Intro Napster

Architecture!

Client-Server

Peer-To-Peer( P2P )

Hybrid

Client-Server Definition

In the client-server model, two process are involved:

Client

Server

Client-Server Architecture

Well known, powerful, reliable server is a data source

Clients request data from server

Very successful model

www ( HTTP ), FTP, Web Service, etc.

Client-Server Limitations

Scalability is hard to achieve

Presents a single point of failure

Requires administration

Peer-To-Peer History

Peer-To-Peer is most commonly known as P2P

Peer-To-Peer file sharing became popular in 1999 with the introduction of Napster.

Peer-To-Peer Definition

Intel : The sharing of computer resources and services by direct exchange between systems.

about sharing : A peer gives some resources and obtain other resources in return.

Peer-To-Peer Architecture

All nodes are both clients and servers

Provide and consume data

No centralized data source

Divide two parts : Pure, Hybrid

Pure Vs Hybrid

Pure P2P :

No centralized server

All peers talk to each other

Hybrid P2P:

just one server for name resolution pourepose

Peer-To-Peer Benefits

The main benefit of P2P is easier to set-up.

All nodes are act as server as well as client

The system the ability to easily scale to any size

There is no single point of failure in the networks

The P2P network is less expensive

Security

The high bandwidth usage required

Files and resources are not centrally organised into a specific ‘ shared area’

Peer-To-Peer Weakness

P2P Applications

File sharing (Napster, Gnutella, Kazaa)

Multiplayer games (Unreal Tournament, DOOM)

Distributed computation (Seti@home)

Ad-hoc networks

Napster

Away to share music files with others

Users upload their list of files to Napster server

You send queries to Napster server for files of interest

Napster server replies with IP address of users with matching files

You connect directly to user A to download file

Any Questions ?!