Mapping the Gnutella Network
Macroscopic Properties of Large Scale P2P
Systems
Ramaswamy N.Vadivelu
Scalab, ASU
03/19/02
Scalab Seminar Series
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Introduction
•Martin Ripeanu, Ian Foster
•University of Chicago
Gnutella: A Quantitative Evaluation
Aims to
•Analyze the overlay network topology.
•Evaluate the generated network traffic.
A P2P system builds a virtual network at the
application level.
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•Topology of this network impacts the application.
•Affects:
communication,performance,reliability,scalability
& anonymity
•Defining Emergent properties.
•Gnutella as a Power Law Network.
•Mapping the virtual network to the physical
network.
•Efficient usage of underlying resources.
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Some issues to be kept in mind
Gnutella Protocol:
•Servents,
•Broadcasting,
•Ping,Pong,Query and File Transfer
•Summary
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Collecting Data
• Gnutella Crawler.
•Initiation.
•List.
•Contact.
•Crawling Strategy.
•Trade off between discovery time and invasiveness.
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Analysis
Network Characteristics:
•A Power Law Network
•N = L –k, K ; Network constant
•Vulnerable to well planned attacks.
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•Small number of devoted users.
Traffic Estimation:
•Eavesdropping using the Crawler.
•Analyzing the distribution of node-node shortest
paths.
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•Most links support similar traffic.
•Total traffic is proportional to no.of connections.
•170,000 connections for a 50,000 node Network
•6Kbps per connection.
•330 TB/month or 1.7% of total traffic in US Internet
backbone(as on 12/00).
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•Focus should be on employing available networking
resources efficiently.
•Store and forward -> Stress on the infrastructure
•Topology mismatch: Experiment
•Internet as a collection of AS’s.
•AS’s are collections of LAN’s.
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•Crossing AS borders is more expensive than
local traffic.
•2-5% of Gnu nodes are within the same AS.
•>40% of nodes are located within the top 10
AS’s.
•-> Most Gnu traffic crosses AS borders.
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Summary
•Gnutella Network has features of a Power Law
Networks.
•Growth of Gnutella dependent on network
usage
•Two areas of further approach
•More efficient P2P designs.
•Smarter routing/communication
mechanisms.
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