This document discusses using scale-free networks to improve search efficiency in unstructured peer-to-peer networks. It proposes the EQUATOR architecture, which creates an overlay network topology based on the scale-free Barabasi-Albert model. Simulation results show that EQUATOR achieves good lookup performance comparable to the ideal Barabasi-Albert network, with low message overhead even under node churn. The scale-free topology allows random walks to efficiently locate resources by directing searches to high-degree "hub" nodes with greater knowledge of the network.
The peer-reviewed International Journal of Engineering Inventions (IJEI) is started with a mission to encourage contribution to research in Science and Technology. Encourage and motivate researchers in challenging areas of Sciences and Technology.
Analytical Modelling of Localized P2P Streaming Systems under NAT ConsiderationIJCNCJournal
NAT has been design to work with Internet client-server structure. The emerged of Peer-to-Peer (P2P)
networks and applications revealed the incompatibility between P2P applications and NAT. Many methods
has been developed and implemented to solve connectivity between peers behind NAT devices.
Nevertheless, various NATing types can’t communicate with one another. In this work, we are going to
study the impact of NAT types on the start-up delay time of peers in P2P streaming systems. We will
demonstrate the ability of NATing to expel peers in P2P live streaming systems. A new neighbour selecting
algorithm will be proposed. This algorithm will utilize NAT-types configurations as a parameter. We have
utilized NS2 simulator to show the performance of the new algorithm in increasing the connectivity,
reducing the number of expelled peers and implementing of locality.
Hybrid Periodical Flooding in Unstructured Peer-to-Peer NetworksZhenyun Zhuang
ICPP 2003
Blind flooding is a popular search mechanism used
current commercial P2P systems because of its simplicity. However, blind flooding among peers or super-peers causes large volume of unnecessary traffic although the response time is short. Some improved statistics-based search mechanisms can reduce the traffic volume but also significantly shrink the query coverage range. In some search mechanisms, not all peers may be reachable creating the so-called partial coverage
problem. Aiming at alleviating the partial coverage problem and reducing the unnecessary traffic, we propose an efficient and adaptive search mechanism, Hybrid Periodical Flooding (HPF). HPF retains the advantages of statistics-based search mechanisms, alleviates the partial coverage problem, and provides the flexibility to adaptively adjust different parameters to
meet different performance requirements. The effectiveness of HPF is demonstrated through simulation studies.
The peer-reviewed International Journal of Engineering Inventions (IJEI) is started with a mission to encourage contribution to research in Science and Technology. Encourage and motivate researchers in challenging areas of Sciences and Technology.
Analytical Modelling of Localized P2P Streaming Systems under NAT ConsiderationIJCNCJournal
NAT has been design to work with Internet client-server structure. The emerged of Peer-to-Peer (P2P)
networks and applications revealed the incompatibility between P2P applications and NAT. Many methods
has been developed and implemented to solve connectivity between peers behind NAT devices.
Nevertheless, various NATing types can’t communicate with one another. In this work, we are going to
study the impact of NAT types on the start-up delay time of peers in P2P streaming systems. We will
demonstrate the ability of NATing to expel peers in P2P live streaming systems. A new neighbour selecting
algorithm will be proposed. This algorithm will utilize NAT-types configurations as a parameter. We have
utilized NS2 simulator to show the performance of the new algorithm in increasing the connectivity,
reducing the number of expelled peers and implementing of locality.
Hybrid Periodical Flooding in Unstructured Peer-to-Peer NetworksZhenyun Zhuang
ICPP 2003
Blind flooding is a popular search mechanism used
current commercial P2P systems because of its simplicity. However, blind flooding among peers or super-peers causes large volume of unnecessary traffic although the response time is short. Some improved statistics-based search mechanisms can reduce the traffic volume but also significantly shrink the query coverage range. In some search mechanisms, not all peers may be reachable creating the so-called partial coverage
problem. Aiming at alleviating the partial coverage problem and reducing the unnecessary traffic, we propose an efficient and adaptive search mechanism, Hybrid Periodical Flooding (HPF). HPF retains the advantages of statistics-based search mechanisms, alleviates the partial coverage problem, and provides the flexibility to adaptively adjust different parameters to
meet different performance requirements. The effectiveness of HPF is demonstrated through simulation studies.
The emerging widespread use of Peer-to-Peer computi
ng is making the P2P Data Mining a
natural choice when data sets are distributed over
such kind of systems. The huge amount of
data stored within the nodes of P2P networks and th
e bigger and bigger number of applications
dealing with them as p2p file-sharing, p2p chatting
, p2p electronic commerce etc.., is moving
the spotlight on this challenging field. In this pa
per we give an overview of two different
approaches for implementing primitives for P2P Data
Mining, trying then to show differences
and similarities. The first one is based on the def
inition of Local algorithms; the second one
relies on the Newscast model of computation.
P2P DOMAIN CLASSIFICATION USING DECISION TREE ijp2p
The increasing interest in Peer-to-Peer systems (such as Gnutella) has inspired many research activities
in this area. Although many demonstrations have been performed that show that the performance of a
Peer-to-Peer system is highly dependent on the underlying network characteristics, much of the
evaluation of Peer-to-Peer proposals has used simplified models that fail to include a detailed model of
the underlying network. This can be largely attributed to the complexity in experimenting with a scalable
Peer-to-Peer system simulator built on top of a scalable network simulator. A major problem of
unstructured P2P systems is their heavy network traffic. In Peer-to-Peer context, a challenging problem
is how to find the appropriate peer to deal with a given query without overly consuming bandwidth?
Different methods proposed routing strategies of queries taking into account the P2P network at hand.
This paper considers an unstructured P2P system based on an organization of peers around Super-Peers
that are connected to Super-Super-Peer according to their semantic domains; in addition to integrating
Decision Trees in P2P architectures to produce Query-Suitable Super-Peers, representing a community
of peers where one among them is able to answer the given query. By analyzing the queries log file, a
predictive model that avoids flooding queries in the P2P network is constructed after predicting the
appropriate Super-Peer, and hence the peer to answer the query. A challenging problem in a schemabased Peer-to-Peer (P2P) system is how to locate peers that are relevant to a given query. In this paper,
architecture, based on (Super-)Peers is proposed, focusing on query routing. The approach to be
implemented, groups together (Super-)Peers that have similar interests for an efficient query routing
method. In such groups, called Super-Super-Peers (SSP), Super-Peers submit queries that are often
processed by members of this group. A SSP is a specific Super-Peer which contains knowledge about: 1.
its Super-Peers and 2. The other SSP. Knowledge is extracted by using data mining techniques (e.g.
Decision Tree algorithms) starting from queries of peers that transit on the network. The advantage of
this distributed knowledge is that, it avoids making semantic mapping between heterogeneous data
sources owned by (Super-)Peers, each time the system decides to route query to other (Super-) Peers.
The set of SSP improves the robustness in queries routing mechanism, and the scalability in P2P
Network. Compared with a baseline approach,the proposal architecture shows the effect of the data
mining with better performance in respect to response time and precision.
Content Sharing over Smartphone-Based Delay-Tolerant NetworksIJERA Editor
With the growing number of smartphone end users, peer-to-peer ad hoc content giving is likely to occur often. Thus, new articles sharing mechanisms must be developed since traditional information delivery schemes will not be efficient with regard to content sharing due to the sporadic connectivity between smartphones on the market. To obtain data delivery such challenging environments, researchers include proposed the employment of store-carry-forward methodologies, in which a node stores a communication and holds it until a forwarding prospect arises through an encounter together with other nodes. Most past works in this field have dedicated to the conjecture of whether two nodes could encounter the other, without thinking about the place and also time from the encounter. In this particular paper, we propose to her discover-predict-deliver as a possible efficient articles sharing scheme for delay-tolerant touch screen phone networks. In this proposed scheme, contents are usually shared while using the mobility information of people. Specifically, our strategy employs the mobility understanding algorithm to spot places inside your own home and outdoor.
A QUERY LEARNING ROUTING APPROACH BASED ON SEMANTIC CLUSTERSijait
Peer-to-peer systems have recently a remarkable success in the social, academic, and commercial communities. A fundamental problem in Peer-to-Peer systems is how to efficiently locate appropriate peers to answer a specific query (Query Routing Problem). A lot of approaches have been carried out to enhance search result quality as well as to reduce network overhead. Recently, researches focus on methods based on query-oriented routing indices. These methods utilize the historical information of past queries and query hits to build a local knowledge base per peer, which represents the user's interests or profile. When a peer forwards a given query, it evaluates the query against its local knowledge base in order to select a set of relevant peers to whom the query will be routed. Usually, an insufficient number of relevant peers is selected from the current peer's local knowledge base thus a broadcast search is investigated which badly affects the approach efficiency. To tackle this problem, we introduce a novel method that clusters peers having similar interests. It exploits not only the current peer's knowledge base but also that of the others in
the cluster to extract relevant peers. We implemented the proposed approach, and tested (i) its retrieval effectiveness in terms of recall and precision, (ii) its search cost in terms of messages traffic and visited peers number. Experimental results show that our approach improves the recall and precision metrics while reducing dramatically messages traffic.
SECURITY CONSIDERATION IN PEER-TO-PEER NETWORKS WITH A CASE STUDY APPLICATIONIJNSA Journal
Peer-to-Peer (P2P) overlay networks wide adoption has also created vast dangers due to the millions of users who are not conversant with the potential security risks. Lack of centralized control creates great risks to the P2P systems. This is mainly due to the inability to implement proper authentication approaches for threat management. The best possible solutions, however, include encryption, utilization of administration, implementing cryptographic protocols, avoiding personal file sharing, and unauthorized downloads. Recently a new non-DHT based structured P2P system is very suitable for designing secured communication protocols. This approach is based on Linear Diophantine Equation (LDE) [1]. The P2P architectures based on this protocol offer simplified methods to integrate symmetric and asymmetric cryptographies’ solutions into the P2P architecture with no need of utilizing Transport Layer Security (TLS), and its predecessor, Secure Sockets Layer (SSL) protocols.
International Journal of Computational Engineering Research(IJCER) ijceronline
International Journal of Computational Engineering Research(IJCER) is an intentional online Journal in English monthly publishing journal. This Journal publish original research work that contributes significantly to further the scientific knowledge in engineering and Technology.
DOMINANT FEATURES IDENTIFICATION FOR COVERT NODES IN 9/11 ATTACK USING THEIR ...IJNSA Journal
In recent days terrorism poses a threat to homeland security. The major problem faced in network analysis is to automatically identify the key player who can maximally influence other nodes in a large relational covert network. The existing centrality based and graph theoretic approach are more concerned about the network structure rather than the node attributes. In this paper an unsupervised framework SoNMine has been developed to identify the key players in 9/11 network using their behavioral profile. The behaviors of nodes are analyzed based on the behavioral profile generated. The key players are identified using the outlier analysis based on the profile and the highly communicating node is concluded to be the most influential person of the covert network. Further, in order to improve
the classification of a normal and outlier node, intermediate reference class R is generated. Based on these three classes the most dominating feature set is determined which further helps to accurately justify the outlier nodes.
TOP 10 AD HOC NETWORKS PAPERS: RECOMMENDED READING – NETWORK RESEARCHIJCNCJournal
The high-level contribution of this paper is a detailed simulation based analysis about the impact of mobility models on the performance of node-disjoint and link-disjoint multi-path routing algorithms for mobile ad hoc networks (MANETs).
For further details contact:
N.RAJASEKARAN B.E M.S 9841091117,9840103301.
IMPULSE TECHNOLOGIES,
Old No 251, New No 304,
2nd Floor,
Arcot road ,
Vadapalani ,
Chennai-26.
www.impulse.net.in
Email: ieeeprojects@yahoo.com/ imbpulse@gmail.com
Study on security and quality of service implementations in p2 p overlay netw...eSAT Publishing House
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
International Journal of Computational Engineering Research(IJCER) is an intentional online Journal in English monthly publishing journal. This Journal publish original research work that contributes significantly to further the scientific knowledge in engineering and Technology
For further details contact:
N.RAJASEKARAN B.E M.S 9841091117,9840103301.
IMPULSE TECHNOLOGIES,
Old No 251, New No 304,
2nd Floor,
Arcot road ,
Vadapalani ,
Chennai-26.
Peer-to-Peer Architecture Case Study Gnutella NetworkMate.docxherbertwilson5999
Peer-to-Peer Architecture Case Study: Gnutella Network
Matei Ripeanu
Computer Science Department,
The University of Chicago
[email protected]
Abstract
Despite recent excitement generated by the P2P
paradigm and despite surprisingly fast deployment of
some P2P applications, there are few quantitative
evaluations of P2P systems behavior. Due to its open
architecture and achieved scale, Gnutella is an
interesting P2P architecture case study. Gnutella, like
most other P2P applications, builds at the application
level a virtual network with its own routing mechanisms.
The topology of this overlay network and the routing
mechanisms used have a significant influence on
application properties such as performance, reliability,
and scalability. We built a ‘crawler’ to extract the
topology of Gnutella’s application level network, we
analyze the topology graph and evaluate generated
network traffic. We find that although Gnutella is not a
pure power-law network, its current configuration has the
benefits and drawbacks of a power-law structure. These
findings lead us to propose changes to Gnutella protocol
and implementations that bring significant performance
and scalability improvements.
1. Introduction
Peer-to-peer systems (P2P) have emerged as a
significant social and technical phenomenon over the last
year. P2P systems provide infrastructure for communities
that share CPU cycles (e.g., Entropia, [email protected])
and/or, storage space (e.g., FreeNet, Gnutella), or that
support interpersonal collaborative environments. Two
factors have fostered the recent explosive growth of such
systems: first, the low cost and high availability of huge
computing and storage resources, and second, increased
network connectivity. As these trends continue, the P2P
paradigm can be expected to become more popular.
Peer-to-peer networks allow individual computers to
communicate directly with each other and to share
information and resources without using specialized
‘servers’. A common characteristic of this new breed of
applications is that they build, at the application level, a
virtual network with its own routing mechanisms. The
topology of this virtual network and the routing
mechanisms used have a significant influence on
application properties such as performance, reliability,
and, in some cases, anonymity. The virtual topology also
determines the communication costs incurred when
running the P2P application.
These considerations have motivated us to conduct a
detailed study of the topology and protocol of a popular
P2P system, Gnutella. In this study, we benefited from
Gnutella’s large existing user base and open architecture,
and, in effect, use the public Gnutella network as a large-
scale, if uncontrolled, testbed. We capture the network
topology, the generated traffic, and the resources’
dynamic behavior. We use our findings to evaluate costs
and benefits of the P2P approach and to investigate
possible improvements to the routing protocol that would
a.
Research Inventy : International Journal of Engineering and Scienceinventy
Research Inventy : International Journal of Engineering and Science is published by the group of young academic and industrial researchers with 12 Issues per year. It is an online as well as print version open access journal that provides rapid publication (monthly) of articles in all areas of the subject such as: civil, mechanical, chemical, electronic and computer engineering as well as production and information technology. The Journal welcomes the submission of manuscripts that meet the general criteria of significance and scientific excellence. Papers will be published by rapid process within 20 days after acceptance and peer review process takes only 7 days. All articles published in Research Inventy will be peer-reviewed.
The emerging widespread use of Peer-to-Peer computi
ng is making the P2P Data Mining a
natural choice when data sets are distributed over
such kind of systems. The huge amount of
data stored within the nodes of P2P networks and th
e bigger and bigger number of applications
dealing with them as p2p file-sharing, p2p chatting
, p2p electronic commerce etc.., is moving
the spotlight on this challenging field. In this pa
per we give an overview of two different
approaches for implementing primitives for P2P Data
Mining, trying then to show differences
and similarities. The first one is based on the def
inition of Local algorithms; the second one
relies on the Newscast model of computation.
P2P DOMAIN CLASSIFICATION USING DECISION TREE ijp2p
The increasing interest in Peer-to-Peer systems (such as Gnutella) has inspired many research activities
in this area. Although many demonstrations have been performed that show that the performance of a
Peer-to-Peer system is highly dependent on the underlying network characteristics, much of the
evaluation of Peer-to-Peer proposals has used simplified models that fail to include a detailed model of
the underlying network. This can be largely attributed to the complexity in experimenting with a scalable
Peer-to-Peer system simulator built on top of a scalable network simulator. A major problem of
unstructured P2P systems is their heavy network traffic. In Peer-to-Peer context, a challenging problem
is how to find the appropriate peer to deal with a given query without overly consuming bandwidth?
Different methods proposed routing strategies of queries taking into account the P2P network at hand.
This paper considers an unstructured P2P system based on an organization of peers around Super-Peers
that are connected to Super-Super-Peer according to their semantic domains; in addition to integrating
Decision Trees in P2P architectures to produce Query-Suitable Super-Peers, representing a community
of peers where one among them is able to answer the given query. By analyzing the queries log file, a
predictive model that avoids flooding queries in the P2P network is constructed after predicting the
appropriate Super-Peer, and hence the peer to answer the query. A challenging problem in a schemabased Peer-to-Peer (P2P) system is how to locate peers that are relevant to a given query. In this paper,
architecture, based on (Super-)Peers is proposed, focusing on query routing. The approach to be
implemented, groups together (Super-)Peers that have similar interests for an efficient query routing
method. In such groups, called Super-Super-Peers (SSP), Super-Peers submit queries that are often
processed by members of this group. A SSP is a specific Super-Peer which contains knowledge about: 1.
its Super-Peers and 2. The other SSP. Knowledge is extracted by using data mining techniques (e.g.
Decision Tree algorithms) starting from queries of peers that transit on the network. The advantage of
this distributed knowledge is that, it avoids making semantic mapping between heterogeneous data
sources owned by (Super-)Peers, each time the system decides to route query to other (Super-) Peers.
The set of SSP improves the robustness in queries routing mechanism, and the scalability in P2P
Network. Compared with a baseline approach,the proposal architecture shows the effect of the data
mining with better performance in respect to response time and precision.
Content Sharing over Smartphone-Based Delay-Tolerant NetworksIJERA Editor
With the growing number of smartphone end users, peer-to-peer ad hoc content giving is likely to occur often. Thus, new articles sharing mechanisms must be developed since traditional information delivery schemes will not be efficient with regard to content sharing due to the sporadic connectivity between smartphones on the market. To obtain data delivery such challenging environments, researchers include proposed the employment of store-carry-forward methodologies, in which a node stores a communication and holds it until a forwarding prospect arises through an encounter together with other nodes. Most past works in this field have dedicated to the conjecture of whether two nodes could encounter the other, without thinking about the place and also time from the encounter. In this particular paper, we propose to her discover-predict-deliver as a possible efficient articles sharing scheme for delay-tolerant touch screen phone networks. In this proposed scheme, contents are usually shared while using the mobility information of people. Specifically, our strategy employs the mobility understanding algorithm to spot places inside your own home and outdoor.
A QUERY LEARNING ROUTING APPROACH BASED ON SEMANTIC CLUSTERSijait
Peer-to-peer systems have recently a remarkable success in the social, academic, and commercial communities. A fundamental problem in Peer-to-Peer systems is how to efficiently locate appropriate peers to answer a specific query (Query Routing Problem). A lot of approaches have been carried out to enhance search result quality as well as to reduce network overhead. Recently, researches focus on methods based on query-oriented routing indices. These methods utilize the historical information of past queries and query hits to build a local knowledge base per peer, which represents the user's interests or profile. When a peer forwards a given query, it evaluates the query against its local knowledge base in order to select a set of relevant peers to whom the query will be routed. Usually, an insufficient number of relevant peers is selected from the current peer's local knowledge base thus a broadcast search is investigated which badly affects the approach efficiency. To tackle this problem, we introduce a novel method that clusters peers having similar interests. It exploits not only the current peer's knowledge base but also that of the others in
the cluster to extract relevant peers. We implemented the proposed approach, and tested (i) its retrieval effectiveness in terms of recall and precision, (ii) its search cost in terms of messages traffic and visited peers number. Experimental results show that our approach improves the recall and precision metrics while reducing dramatically messages traffic.
SECURITY CONSIDERATION IN PEER-TO-PEER NETWORKS WITH A CASE STUDY APPLICATIONIJNSA Journal
Peer-to-Peer (P2P) overlay networks wide adoption has also created vast dangers due to the millions of users who are not conversant with the potential security risks. Lack of centralized control creates great risks to the P2P systems. This is mainly due to the inability to implement proper authentication approaches for threat management. The best possible solutions, however, include encryption, utilization of administration, implementing cryptographic protocols, avoiding personal file sharing, and unauthorized downloads. Recently a new non-DHT based structured P2P system is very suitable for designing secured communication protocols. This approach is based on Linear Diophantine Equation (LDE) [1]. The P2P architectures based on this protocol offer simplified methods to integrate symmetric and asymmetric cryptographies’ solutions into the P2P architecture with no need of utilizing Transport Layer Security (TLS), and its predecessor, Secure Sockets Layer (SSL) protocols.
International Journal of Computational Engineering Research(IJCER) ijceronline
International Journal of Computational Engineering Research(IJCER) is an intentional online Journal in English monthly publishing journal. This Journal publish original research work that contributes significantly to further the scientific knowledge in engineering and Technology.
DOMINANT FEATURES IDENTIFICATION FOR COVERT NODES IN 9/11 ATTACK USING THEIR ...IJNSA Journal
In recent days terrorism poses a threat to homeland security. The major problem faced in network analysis is to automatically identify the key player who can maximally influence other nodes in a large relational covert network. The existing centrality based and graph theoretic approach are more concerned about the network structure rather than the node attributes. In this paper an unsupervised framework SoNMine has been developed to identify the key players in 9/11 network using their behavioral profile. The behaviors of nodes are analyzed based on the behavioral profile generated. The key players are identified using the outlier analysis based on the profile and the highly communicating node is concluded to be the most influential person of the covert network. Further, in order to improve
the classification of a normal and outlier node, intermediate reference class R is generated. Based on these three classes the most dominating feature set is determined which further helps to accurately justify the outlier nodes.
TOP 10 AD HOC NETWORKS PAPERS: RECOMMENDED READING – NETWORK RESEARCHIJCNCJournal
The high-level contribution of this paper is a detailed simulation based analysis about the impact of mobility models on the performance of node-disjoint and link-disjoint multi-path routing algorithms for mobile ad hoc networks (MANETs).
For further details contact:
N.RAJASEKARAN B.E M.S 9841091117,9840103301.
IMPULSE TECHNOLOGIES,
Old No 251, New No 304,
2nd Floor,
Arcot road ,
Vadapalani ,
Chennai-26.
www.impulse.net.in
Email: ieeeprojects@yahoo.com/ imbpulse@gmail.com
Study on security and quality of service implementations in p2 p overlay netw...eSAT Publishing House
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
International Journal of Computational Engineering Research(IJCER) is an intentional online Journal in English monthly publishing journal. This Journal publish original research work that contributes significantly to further the scientific knowledge in engineering and Technology
For further details contact:
N.RAJASEKARAN B.E M.S 9841091117,9840103301.
IMPULSE TECHNOLOGIES,
Old No 251, New No 304,
2nd Floor,
Arcot road ,
Vadapalani ,
Chennai-26.
Peer-to-Peer Architecture Case Study Gnutella NetworkMate.docxherbertwilson5999
Peer-to-Peer Architecture Case Study: Gnutella Network
Matei Ripeanu
Computer Science Department,
The University of Chicago
[email protected]
Abstract
Despite recent excitement generated by the P2P
paradigm and despite surprisingly fast deployment of
some P2P applications, there are few quantitative
evaluations of P2P systems behavior. Due to its open
architecture and achieved scale, Gnutella is an
interesting P2P architecture case study. Gnutella, like
most other P2P applications, builds at the application
level a virtual network with its own routing mechanisms.
The topology of this overlay network and the routing
mechanisms used have a significant influence on
application properties such as performance, reliability,
and scalability. We built a ‘crawler’ to extract the
topology of Gnutella’s application level network, we
analyze the topology graph and evaluate generated
network traffic. We find that although Gnutella is not a
pure power-law network, its current configuration has the
benefits and drawbacks of a power-law structure. These
findings lead us to propose changes to Gnutella protocol
and implementations that bring significant performance
and scalability improvements.
1. Introduction
Peer-to-peer systems (P2P) have emerged as a
significant social and technical phenomenon over the last
year. P2P systems provide infrastructure for communities
that share CPU cycles (e.g., Entropia, [email protected])
and/or, storage space (e.g., FreeNet, Gnutella), or that
support interpersonal collaborative environments. Two
factors have fostered the recent explosive growth of such
systems: first, the low cost and high availability of huge
computing and storage resources, and second, increased
network connectivity. As these trends continue, the P2P
paradigm can be expected to become more popular.
Peer-to-peer networks allow individual computers to
communicate directly with each other and to share
information and resources without using specialized
‘servers’. A common characteristic of this new breed of
applications is that they build, at the application level, a
virtual network with its own routing mechanisms. The
topology of this virtual network and the routing
mechanisms used have a significant influence on
application properties such as performance, reliability,
and, in some cases, anonymity. The virtual topology also
determines the communication costs incurred when
running the P2P application.
These considerations have motivated us to conduct a
detailed study of the topology and protocol of a popular
P2P system, Gnutella. In this study, we benefited from
Gnutella’s large existing user base and open architecture,
and, in effect, use the public Gnutella network as a large-
scale, if uncontrolled, testbed. We capture the network
topology, the generated traffic, and the resources’
dynamic behavior. We use our findings to evaluate costs
and benefits of the P2P approach and to investigate
possible improvements to the routing protocol that would
a.
Research Inventy : International Journal of Engineering and Scienceinventy
Research Inventy : International Journal of Engineering and Science is published by the group of young academic and industrial researchers with 12 Issues per year. It is an online as well as print version open access journal that provides rapid publication (monthly) of articles in all areas of the subject such as: civil, mechanical, chemical, electronic and computer engineering as well as production and information technology. The Journal welcomes the submission of manuscripts that meet the general criteria of significance and scientific excellence. Papers will be published by rapid process within 20 days after acceptance and peer review process takes only 7 days. All articles published in Research Inventy will be peer-reviewed.
The emerging widespread use of Peer-to-Peer computing is making the P2P Data Mining a
natural choice when data sets are distributed over such kind of systems. The huge amount of
data stored within the nodes of P2P networks and the bigger and bigger number of applications
dealing with them as p2p file-sharing, p2p chatting, p2p electronic commerce etc.., is moving
the spotlight on this challenging field. In this paper we give an overview of two different
approaches for implementing primitives for P2P Data Mining, trying then to show differences
and similarities. The first one is based on the definition of Local algorithms; the second one
relies on the Newscast model of computation.
International Journal of Computational Engineering Research(IJCER) is an intentional online Journal in English monthly publishing journal. This Journal publish original research work that contributes significantly to further the scientific knowledge in engineering and Technology.
COMMUNICATIONS OF THE ACM November 2004Vol. 47, No. 11 15.docxmonicafrancis71118
COMMUNICATIONS OF THE ACM November 2004/Vol. 47, No. 11 15
N
etworks are hot. The
Internet has made it pos-
sible to observe and mea-
sure linkages
representing relationships of
all kinds. We now recognize
networks everywhere: air
traffic, banking, chemical
bonds, data communications,
ecosystems, finite element
grids, fractals, interstate
highways, journal citations,
material structures, nervous
systems, oil pipelines, orga-
nizational networks, power
grids, social structures, trans-
portation, voice communica-
tion, water supply, Web
URLs, and more.
Several fields are collabo-
rating on the development of
network theory, measurement,
and mapping: mathematics
(graph theory), sociology (net-
works of influence and communi-
cation), computing (Internet), and
business (organizational net-
works). This convergence has pro-
duced useful results for risk
assessment and reduction in com-
plex infrastructure networks,
attacking and defending networks,
protecting against network con-
nectivity failures, operating busi-
nesses, spreading epidemics
(pathogens as well as computer
viruses), and spreading innova-
tion. Here, I will survey the fun-
damental laws of networks that
enable these results.
Defining a Network
A network is usually defined as a
set of nodes and links. The nodes
represent entities such as persons,
machines, molecules, documents,
or businesses; the links represent
relationships between pairs of
entities. A link can be directed
(one-way relationship) or undi-
rected (mutual relationship). A
hop is a transition from one node
to another across a single link
separating them. A path is a series
of hops. Networks are very gen-
eral: they can represent any kind
of relation among entities.
Some common network
topologies (interconnection pat-
terns) have their own names:
clique or island (a connected sub-
network that may be isolated
from other cliques), hierarchical
network (tree structured), hub-
and-spoke network (a special
node, the hub, connected directly
to every other node), and multi-
hub network (several hubs con-
nected directly to many nodes).
Some network topologies are
planned, such as the electric grid,
the interstate highway system, or
Network Laws
M
IC
H
A
EL
S
LO
A
N
Peter J. Denning
Many networks, physical and social, are complex and scale-invariant.
This has important implications from the spread of epidemics and
innovations to protection from attack.
The Profession of IT
16 November 2004/Vol. 47, No. 11 COMMUNICATIONS OF THE ACM
the air traffic system; others are
unplanned. In his seminal papers
about the Internet, Paul Baran
proposed that a planned, distrib-
uted network would be more
resilient to failures than a hub-
and-spoke network.
A host of physical systems eas-
ily fit a network model. Perhaps
less obvious is that human social
networks also fit the model. The
individuals of an organization are
linked by their relationships—
who emails whom, who seeks
advice from whom, or who influ-
ences w.
International Journal of Computational Engineering Research(IJCER)ijceronline
International Journal of Computational Engineering Research(IJCER) is an intentional online Journal in English monthly publishing journal. This Journal publish original research work that contributes significantly to further the scientific knowledge in engineering and Technology
In the last decade Peer to Peer technology has been thoroughly explored, becauseit overcomes many limitations compared to the traditional client server paradigm. Despite its advantages over a traditional approach, the ubiquitous availability of high speed, high bandwidth and low latency networks has supported the traditional client-server paradigm. Recently, however, the surge of streaming services has spawned renewed interest in Peer to Peer technologies. In addition, services like geolocation databases and browser technologies like Web-RTC make a hybrid approach attractive.
In this paper we present algorithms for the construction and the maintenance of a hybrid P2P overlay multicast tree based on topological distances. The essential idea of these algorithms is to build a multicast tree by choosing neighbours close to each other. The topological distances can be easily obtained by the browser using the geolocation API. Thus the implementation of algorithms can be done web-based in a distributed manner.
We present proofs of our algorithms as well as experimental results and evaluations.
Content Distribution for Peer-To-Peer Overlays on Mobile Adhoc Networks to Fu...Editor IJCATR
Peer-to-peer (P2P) networks existing on a MANET are a natural evolution since both are decentralized and have dynamic
topologies. As MANETs grow in use due to the increasing popularity of wireless mesh and 4G networks, it is expected that P2P
applications will remain as a popular means of obtaining files. Network coding has been shown as an efficient means of sharing large
Files in a P2P network. With network coding, all file blocks have the same relative importance. This paper presents an efficient
content distribution scheme that uses network coding to share large files in a P2P overlay running on a MANET. Peers request file
blocks from multiple server nodes and servers multicast blocks to multiple receivers, providing efficient multipoint-to-multipoint
communication.
Simulation results show that compared to other common download techniques, the proposed scheme performs very well, having lower
download time and energy consumption. Also, more peers participate in uploading the file, resulting in greater fairness.
The International Journal of Engineering and Science (IJES)theijes
The International Journal of Engineering & Science is aimed at providing a platform for researchers, engineers, scientists, or educators to publish their original research results, to exchange new ideas, to disseminate information in innovative designs, engineering experiences and technological skills. It is also the Journal's objective to promote engineering and technology education. All papers submitted to the Journal will be blind peer-reviewed. Only original articles will be published.
Similar to Scale-Free Networks to Search in Unstructured Peer-To-Peer Networks (20)
Final project report on grocery store management system..pdfKamal Acharya
In today’s fast-changing business environment, it’s extremely important to be able to respond to client needs in the most effective and timely manner. If your customers wish to see your business online and have instant access to your products or services.
Online Grocery Store is an e-commerce website, which retails various grocery products. This project allows viewing various products available enables registered users to purchase desired products instantly using Paytm, UPI payment processor (Instant Pay) and also can place order by using Cash on Delivery (Pay Later) option. This project provides an easy access to Administrators and Managers to view orders placed using Pay Later and Instant Pay options.
In order to develop an e-commerce website, a number of Technologies must be studied and understood. These include multi-tiered architecture, server and client-side scripting techniques, implementation technologies, programming language (such as PHP, HTML, CSS, JavaScript) and MySQL relational databases. This is a project with the objective to develop a basic website where a consumer is provided with a shopping cart website and also to know about the technologies used to develop such a website.
This document will discuss each of the underlying technologies to create and implement an e- commerce website.
Quality defects in TMT Bars, Possible causes and Potential Solutions.PrashantGoswami42
Maintaining high-quality standards in the production of TMT bars is crucial for ensuring structural integrity in construction. Addressing common defects through careful monitoring, standardized processes, and advanced technology can significantly improve the quality of TMT bars. Continuous training and adherence to quality control measures will also play a pivotal role in minimizing these defects.
Welcome to WIPAC Monthly the magazine brought to you by the LinkedIn Group Water Industry Process Automation & Control.
In this month's edition, along with this month's industry news to celebrate the 13 years since the group was created we have articles including
A case study of the used of Advanced Process Control at the Wastewater Treatment works at Lleida in Spain
A look back on an article on smart wastewater networks in order to see how the industry has measured up in the interim around the adoption of Digital Transformation in the Water Industry.
Cosmetic shop management system project report.pdfKamal Acharya
Buying new cosmetic products is difficult. It can even be scary for those who have sensitive skin and are prone to skin trouble. The information needed to alleviate this problem is on the back of each product, but it's thought to interpret those ingredient lists unless you have a background in chemistry.
Instead of buying and hoping for the best, we can use data science to help us predict which products may be good fits for us. It includes various function programs to do the above mentioned tasks.
Data file handling has been effectively used in the program.
The automated cosmetic shop management system should deal with the automation of general workflow and administration process of the shop. The main processes of the system focus on customer's request where the system is able to search the most appropriate products and deliver it to the customers. It should help the employees to quickly identify the list of cosmetic product that have reached the minimum quantity and also keep a track of expired date for each cosmetic product. It should help the employees to find the rack number in which the product is placed.It is also Faster and more efficient way.
Automobile Management System Project Report.pdfKamal Acharya
The proposed project is developed to manage the automobile in the automobile dealer company. The main module in this project is login, automobile management, customer management, sales, complaints and reports. The first module is the login. The automobile showroom owner should login to the project for usage. The username and password are verified and if it is correct, next form opens. If the username and password are not correct, it shows the error message.
When a customer search for a automobile, if the automobile is available, they will be taken to a page that shows the details of the automobile including automobile name, automobile ID, quantity, price etc. “Automobile Management System” is useful for maintaining automobiles, customers effectively and hence helps for establishing good relation between customer and automobile organization. It contains various customized modules for effectively maintaining automobiles and stock information accurately and safely.
When the automobile is sold to the customer, stock will be reduced automatically. When a new purchase is made, stock will be increased automatically. While selecting automobiles for sale, the proposed software will automatically check for total number of available stock of that particular item, if the total stock of that particular item is less than 5, software will notify the user to purchase the particular item.
Also when the user tries to sale items which are not in stock, the system will prompt the user that the stock is not enough. Customers of this system can search for a automobile; can purchase a automobile easily by selecting fast. On the other hand the stock of automobiles can be maintained perfectly by the automobile shop manager overcoming the drawbacks of existing system.
CFD Simulation of By-pass Flow in a HRSG module by R&R Consult.pptxR&R Consult
CFD analysis is incredibly effective at solving mysteries and improving the performance of complex systems!
Here's a great example: At a large natural gas-fired power plant, where they use waste heat to generate steam and energy, they were puzzled that their boiler wasn't producing as much steam as expected.
R&R and Tetra Engineering Group Inc. were asked to solve the issue with reduced steam production.
An inspection had shown that a significant amount of hot flue gas was bypassing the boiler tubes, where the heat was supposed to be transferred.
R&R Consult conducted a CFD analysis, which revealed that 6.3% of the flue gas was bypassing the boiler tubes without transferring heat. The analysis also showed that the flue gas was instead being directed along the sides of the boiler and between the modules that were supposed to capture the heat. This was the cause of the reduced performance.
Based on our results, Tetra Engineering installed covering plates to reduce the bypass flow. This improved the boiler's performance and increased electricity production.
It is always satisfying when we can help solve complex challenges like this. Do your systems also need a check-up or optimization? Give us a call!
Work done in cooperation with James Malloy and David Moelling from Tetra Engineering.
More examples of our work https://www.r-r-consult.dk/en/cases-en/
Event Management System Vb Net Project Report.pdfKamal Acharya
In present era, the scopes of information technology growing with a very fast .We do not see any are untouched from this industry. The scope of information technology has become wider includes: Business and industry. Household Business, Communication, Education, Entertainment, Science, Medicine, Engineering, Distance Learning, Weather Forecasting. Carrier Searching and so on.
My project named “Event Management System” is software that store and maintained all events coordinated in college. It also helpful to print related reports. My project will help to record the events coordinated by faculties with their Name, Event subject, date & details in an efficient & effective ways.
In my system we have to make a system by which a user can record all events coordinated by a particular faculty. In our proposed system some more featured are added which differs it from the existing system such as security.
Scale-Free Networks to Search in Unstructured Peer-To-Peer Networks
1. IOSR Journal of Computer Engineering (IOSR-JCE)
e-ISSN: 2278-0661, p- ISSN: 2278-8727Volume 12, Issue 4 (Jul. - Aug. 2013), PP 12-17
www.iosrjournals.org
www.iosrjournals.org 12 | Page
Scale-Free Networks to Search in Unstructured Peer-To-Peer
Networks
1
Yadma srinivas reddy, 2
Mr.D. Raman,
1 (M.Tech, Cse, Vardhaman college of engineering)
2 (Associate professor , CSE, Vardhaman college if engineering)
Abstract: Unstructured peer-to-peer file sharing networks are very popular in the market. They introduce
network traffic. The resultant networks are not perform search efficiently because existing overlay topology
formation algorithms are creates unstructured P2P networks without performance guarantees. In this paper,
We compares structured and unstructured overlays, Showing through analytical and simulation results how an
unstructured solution relying on a scale-free topology is an effective option to deploy for offering services based
on equivalent servants. Based on this result, The EQUivalent servAnt locaTOR (EQUATOR) architecture, which
overcomes the issues related to the deployment of a scale-free topology for service location in a real network,
mainly due to the static nature of the ideal scale-free construction algorithm and the lack of a global knowledge
of the participating peers. Simulation results confirmed the effectiveness of EQUATOR, showing how it offers
good lookup performance in combination with low message overhead and high resiliency to node churn and
failures. Some possible future works are introduced and are related to some complementary issues ranging from
the proximity-aware selection of servants to the introduction of proper incentives to encourage nodes to join the
EQUATOR overlay and offer their resources.
Keywords: peer to peer systems, Random Networks, Scale-Free Networks, Communication Networks, Socio-
Technical Networks, Diffusion.
I. Introduction
PEER-TO-PEER networks have been widely Spred out in the Internet, and they provide different
services such as file sharing, information retrieval, media streaming. P2P applications are popular because they
primarily provide low entry barriers and self-scaling. Object search is an important task in P2P applications.
Gnutella is a popular P2P search protocol in the mass market. Because Gnutella networks are unstructured,
Peers participating in networks connect to one another randomly, peers search objects in the networks through
message flooding. To flood a message, an inquiry peer broadcasts the message to its neighbours. The broadcast
message is associated with a positive integer time-to-live (TTL) value. Upon receiving a message, the peer
decreases the TTL value associated with the message by 1 and then relays the message with the updated TTL
value to its neighbours, except the one sending the message to j, if the TTL value remains positive. Aside from
forwarding the message to the neighbours, j searches its local store to see if it can provide the objects requested
by peer i. Conceptually, if j has the requested objects and is ready to supply them, then j either directly sends i
the objects or returns the objects to the overlay path where the query message traverses from i to j. The search
performance in Gnutella is like unstructured P2P networks. Existing orthogonal techniques in the literature for
improving search performance in unstructured P2P networks include indexing, replications, super peer
architectures and overlay topologies, among others. In this paper, we primarily study the square-root topology
technique for unstructured P2P networks, aiming to enhance search efficiency and effectiveness.
The P2P network minimize the overlay path length between any two peers to reduce the query response time.
The probability of peer j being the neighbor of peer i increasing if j shares more common interests with i. we
first observe that existing P2P file sharing networks exhibit the power-law file sharing pattern. our proposal has
the following unique features:
In a constant probability, the search hop count between any two nodes is Oðlnc1 NÞ,where 1< c1<2 is
a small constant, and N is the number of active peers participating in the network.
In a constant probability of approximately 100 percent, the peers on the search path from the querying
peer to the destination peer progressively and effectively exploit their similarity.
Whereas some solutions require centralized servers to help organize the system, our proposal needs no
centralized servers to participate in. our solution is mathematically provable and provides performance
guarantees. Moreover, we suggest a search protocol to take advantage of the peer similarity exhibited by our
proposed overlay network. Noticeably, one extra finding in our performance analysis reveals that semantic P2P
Submitted date 17 June 2013 Accepted Date: 22 June 2013
2. Scale-Free Networks to Search in Unstructured Peer-To-Peer Networks
www.iosrjournals.org 13 | Page
networks, which not only attempt to cluster semantic closest peers but also suggest to interconnect peers
selected uniformly at random, cannot work well by efficiently exploiting the similarity of peers for searches.
Particularly, if any peer i on the path has to find another peer j, which is more similar to the destination peer d
than i, to receive and forward the query toward d. Aside from having a rigorous performance analysis, our
theoretical analysis is validated in simulations. we compare our proposal with two representative distributed
algorithms. With our similarity aware search protocol, we conclude that the overlay networks that exploit the
similarity of participating peers can considerably reduce the query traffic than the search protocol based on blind
flooding.
II. Our Proposal: Scale-Free Networks:
Network Models
ER- and scale-free networks as well as their main characteristics and the processes by which they are
created. ER-networks, because of their diminishing importance for modelling real world networks, are only
briefly introduced to show their important differences from scale-free networks. The basics of network analysis
are discussed first to enable a better understanding.
2.1 Basics of Network Analyses
In an undirected network graph, the degree of a node is defined as the number of edges it possesses. If
all the nodes of a network that share the same degree are counted and the results are sorted by increasing degree
a function like that is most likely to occur. There are no nodes with degree zero, because these nodes would not
be connected to the network. The network exhibits a majority of nodes with degree one to three and rather fewer
nodes with a degree greater than seven. The degree distribution of networks does not have to be continuous. If
one node of the network were randomly chosen, the probability of obtaining a node with only one to three edges
is much higher than that of obtaining a node with a degree higher than seven. Therefore it is possible to define a
probability distribution function that returns the probability that node v has j edges within network N. The
concept of the degree distribution of a network has important consequences for the properties of a network and
will be frequently used in the paragraphs that follow. It will be seen that deviation from the normal distribution
will lead to new results in terms of diffusion within networks. Clustering within networks is another important
factor when analyzing networks. It is interesting to know how well nodes are interconnected within a specified
area of the network. Using the ratio between existing and possible relations, a clustering coefficient may be
computed.
If a node has z nearest neighbours, a maximum of edges is possible between them. Watts and Strogatz
defined the clustering coefficient for node v as the ratio of the number I of existing nodes to the possible number
of edges between the direct neighbours of node v As for the degree distribution, the clustering coefficient plays
an important role when analyzing networks in terms of important properties like diffusion, which
The path length between two nodes of a network is defined as the number of edges between them. The minimal
path length is the shortest path between two nodes. The average path length is the average of all the minimal
path lengths between all pairs of nodes in a network.
2.2 ER-Networks
Since the seminal paper of Erdo and Renyi in 1959, Random network theory dominated scientific
thinking [Bara03]. Real world networks had been thought to be too complex to understand and therefore held to
be random. In the absence of other well-understood network models, random
Networks were widely used when modelling networks. The process of creating an ER-network depends on
probability p. For a network with n nodes each possible pair of distinct nodes are connected with an edge with
probability p.
An ER-network has the property that the majority of nodes have a degree that is close to the average
degree of the overall network and that there is not much deviation from the average below and above it. It has
been shown that the distribution of links follows a Poisson distribution. Knowing the degree distribution, the
average path length, and the clustering coefficient of ER-networks, it is feasible to analyze their different
behaviour compared to scale-free networks. ER-networks are still used in some types of models. The following
chapters will show that ER-networks may not be applic Able for every purpose, because they lack Some of the
properties of other classes of Networks.
2.3 Scale-Free Networks
When Albert et al. started to map the internet in 1999, they did not know that they were about to
influence network research in a sustained way. Because of the Diverse interests of every internet user and The
gigantic number of web pages, the linkages between web pages were thought to be randomly linked as a random
network. The results of their study have disagreed With this expectation in a surprising way. Only a few pages
3. Scale-Free Networks to Search in Unstructured Peer-To-Peer Networks
www.iosrjournals.org 14 | Page
have the majority of links, whereas most pages are only very sparsely connected. More than 80% of all Pages
visited have 4 links or less, only 0.01% of the pages are linked to more than 1000 other pages. If the nodes with
one, two, three, etc. connections are counted, and the numbers are plotted into a chart as in the middle of the
distribution of edges becomes visible. There are many nodes with only a few links and a few nodes with a large
number of links. If the distribution of edges is plotted in a logarithmic chart, as in right, the power-law nature of
the distribution appears in a straight curve with a slope of G from equation. The difference from ER-networks
now becomes evident. The probability distribution function of the degree j of scale-free networks is described
with j > 0 and g > 0, with g called the scale-free exponent. The term scale-free is a mathematical expression
which stands for power-law distributions as in equation. The power-law distributions belong to the Class of
leptokurtic or fat-tailed distributions. They deviate from the Poisson distribution in two ways: they have higher
peaks and fat tails.
III. Experimental Results for Equator
This section presents some simulation results on the EQUATOR architecture. We first validate our
overlay construction algorithm, which we show to result in a scale-free topology. We also show how
EQUATOR is comparable to the ideal Barabasi-Albert network in terms of lookup performance. We then
elaborate on the system parameters, also focusing on the lookup and advertisement overhead at nodes. Finally,
we investigate the behaviour of our solution in different scenarios triggered by different kinds of peers.
3.1 Structured overlays
We first investigate the possibility to deploy a structured overlay based on a general DHT, as it has
been proposed in [19] for the P2PSIP architecture. Since in our scenario all peers provide the same functionality,
the number of copies predominates over the number of distinct
Services and therefore the ability of DHTs to locate a specific resource are of little help. Therefore,
[19] proposes to use the DHT in a more clever way: queries are performed by randomly selecting a target key
and then moving in the overlay to reach this target. Since it does not cause further complexity and possibly
improves the system performance, we introduce an additional feature to this querying mechanism: during the
lookup process, any node encountered along the path is checked for availability and can be selected as a servant
for the querying user. Notice that this operating mode makes the approach independent of the adopted DHT. In
fact, only the overlay topology is of interest in our context. In other words, we adopt the topology of a generic
DHT, with a fixed number of neighbours for each node, but we use a different routing mechanism. This solution
will be however referred to as DHT in the rest of the paper. The idea of using a DHT for our scenario of
equivalent servants is especially interesting in case a DHT has to be implemented anyway for some other
services. For example, P2PSIP already uses a structured overlay to index all possible targets of a multimedia
communication, i.e., all the user agents registered in the SIP domain. Using the same DHT to locate, if
necessary, a relay node to support the communication may be a considerable advantage for that application,
which needs to maintain only one overlay structure that can be used for both functions.
3.2 Unstructured overlays
An efficient unstructured overlay is characterized by high lookup performance and small amount of
traffic required to maintain the overlay. Both parameters are influenced by the topology and the operating
principles of the overlay. This section elaborates on these aspects in the context of services based on equivalent
servants, proposing to adopt a scale-free topology and motivating this choice. An interesting lookup solution
that avoids the deleterious traffic overhead generated by flooding-based queries is the adoption of a service
lookup based on random walks encompassing a bounded number of nodes. Within this technique, the service
request is forwarded, at each node, to a peer randomly selected among its neighbours. If the encountered node is
available or knows an available servant, the procedure terminates. The knowledge of nodes can be improved
through proper advertisement messages containing the node itself and other participating peers, thus
implementing a so called epidemic dissemination algorithm.
The effectiveness of random walks depends on the overlay topology adopted in the system. Among
other possibilities, a scale-free topology may offer interesting features. In a scale free network, the node degree
distribution follows a power-law P (n) = cn^r, where P (n) is the probability that a node has n connections and c
is a normalization factor. Hence, only few nodes have a high degree, i.e., are aware of the existence of a large
number of participating peers. The idea is that directing random walks toward hubs means looking for the
service where there is a great knowledge of servants. This ensures high lookup performance with respect to an
overlay based on a balanced Degree distribution where service requests are randomly distributed among peers.
This result derives from a well-known property of queuing systems, which says that a unique M/G/k/k
queuing system servicing an arrival process with rate performs better than k separated M/G/1/1 systems each
one servicing an arrival process with rate k. In essence, concentrating the traffic on some nodes that have a deep
4. Scale-Free Networks to Search in Unstructured Peer-To-Peer Networks
www.iosrjournals.org 15 | Page
knowledge of the network provides better performance than accurately distributing the requests among all
nodes, as random solutions try to do. Effectiveness of random walks in scale free networks due to the greater
knowledge of resources available at the hubs. In order to achieve high lookup performance, hubs should have a
deep knowledge about the other participating peers: the greater the number of peers known by a given node, the
higher the probability for a user to find an available servant in a short time.
Since the epidemic dissemination is based on flooding, the overlay topology has a deep impact not only
on peers known by each node, but also on the resulting network efficiency. In fact, the greater the average path
length between nodes, the higher the depth of the flooding that is needed for an adequate spread of the
information, which may cause an unsustainable load on the network. The scale-free topology also ensures a
good efficiency of epidemic dissemination algorithms as exhibits a small average path length. In essence, a large
number of advertisement messages reach the hubs even with a small dissemination depth (namely, the number
of hops encompassed by advertisement messages before elapsing) and a small out-degree. Another interesting
feature of scale-free networks is that they can scale to an arbitrarily large network size without Modifying the
degree distribution of nodes, which continues to follow the same law? This ensures that new hubs are
automatically created when the network size grows, therefore maintaining the above described properties.
In essence, scale-free networks potentially combine the advantages of centralized indexing and Totally
distributed solutions. One of the most popular mechanisms to build a scale-free network was proposed by
Barabasi and Albert and for this reason is referred to as Barabasi-Albert model. Let m denote the out-degree of a
node and d denote its in-degree. The Barabasi-Albert model requires a set of m0 nodes to be already in the
system at the beginning of the process. Then, each entering node connects to m existing nodes, chosen
proportionally to their popularity. This process is known as Preferential attachment. This network formation
algorithm results in a scale free network characterized by a node degree distribution P (n) = cn−3 and an average
path length which behaves The Barabasi-Albert model is used as a reference in the rest of the paper. Although in
general P (n) = P (m + d), in this case we are interested in the in degree of a node as it represents its popularity,
i.e., it counts the number of nodes that send their advertisements to it. Thereby, without losing in significance,
we consider P (n) = P (d) i.e., the distribution of the in-degree of nodes in the following. The Barabási-Albert
model is an ideal network formation algorithm that requires a global knowledge of the existing nodes. Clearly,
this is not feasible in a real network. Hence, while this section shows the effectiveness of a scale-free solution
will present an overlay construction algorithm based on a limited network knowledge which approximates the
Barabasi-Albert model.
3.3 Proactive Replication
The square-root topology is complementary to the square-root replication. In situations where it is
feasible to proactively replicate content, the square-root replication specifies that the number of copies made of
content should be proportional to the square root of the popularity of the content. The square-root topology can
be used whether or not proactive replication is used, but the combination of the two techniques can provide
significant performance benefits. We conducted an experiment where we proactively replicated content
according to the square-root replication. Each peer was assigned capacity equal to twice the content they were
already storing, and this extra capacity was used to store proactively replicated copies. We then connected peers
in the square-root, high-skew power-law, and low-skew power-law topologies, and measured the performance
of random walk searches. Again, G= 10. The results are shown in Figure 2. As expected, proactive replication
provided better performance than no replication. Proactive replication performs best with the square-root
topology, requiring only 2,830 messages per search, 42 percent less than in the low-skew power-law network
and 56 percent less than in the high-skew power-law network.
Proactive replication makes more copies of the documents that a search will match, while the square-
root topology makes it easier for the search to get to the peers where the documents are stored. The combination
of the two techniques provides more efficiency than either technique alone. For example, in our experiment, the
square root topology with proactive replication required 68 percent fewer messages than the square root
topology without replication.
3.4 Other search walk techniques
Next, we examined the performance of other walk-based techniques on different topologies. We
compared three other techniques based on random walks:
• Biased high degree: messages are preferentially forwarded to neighbors that have the highest degree.
• Most results: messages are forwarded preferentially to neighbors that have returned the most results for the
past 10 queries.
• Fewest result hops: messages are forwarded preferentially to neighbors that returned results for the past 10
queries who have traveled the fewest average hops .
5. Scale-Free Networks to Search in Unstructured Peer-To-Peer Networks
www.iosrjournals.org 16 | Page
In each case, ties are broken randomly. For the biased high degree technique, we examined both neighbour
indexing and no neighbour indexing. Although describes several ways to route searches in addition to most
results and fewest result hops, these two techniques represent the “best” that the authors studied: fewest result
hops requires the least bandwidth, while most results has the best chance of finding the requested number of
matching documents.
Each case the square-root topology is best. The most improvement is seen with the biased high degree
technique, where the improvement on going from the high-skew power-law topology to the square-root
topology is 52 percent. Large improvements are achieved with the fewest result hops technique and most results.
The smallest improvement observed was for the biased high degree technique with neighbor indexing. square-
root topology offers a 16 percent decrease in messages compared to the lowskew power-law topology. Overall,
the square-root topology provides the best performance, even with the extremely efficient biased high
degree/neighbor indexing combination. Moreover, the square-root topology can be used even when neighbor
indexing is not feasible. The combination of square-root topology, square-root replication and biased high
degree walking with neighbor indexing provides even better performance. Our results indicate that this approach
is extremely efficient, requiring only 248 messages per search on average. Again, the square root topology is
better than the power law topology when square-root replication and neighbor indexing are used.
Using all three techniques together results in a searching mechanism that contacts less than 2% of the
system peers on average while still finding sufficient results. Finally, the results so far assume state-keep ing,
where peers keep state about where the search has been. Then, peers can avoid forwarding searches to
neighbours that the search has already visited. We also ran experiments for no state keeping. The results
demonstrate that the square-root topology is better than power-law topologies, whether or not statekeeping is
used.
3.5 Other Topologies
We also tested the square-root topology in comparison to several other network structures. First, we
compared against two simple structures:
• Constant-degree topology: every peer has the same number of neighbors. In our simulations, each peer had
five neighbors.
• Proportional topology: every peer had a degree proportional to their popularity gk.
Our results show that the square-root topology is best, requiring 10 percent fewer messages than the constant
degree network, and 7 percent fewer messages than the proportional topology. Although the improvement is
smaller than when comparing the square-root topology to power-law topologies, these results again demonstrate
that the square-root topology is best. Moreover, the cost of maintaining the square-root topology is low, as we
discuss in Section 4, requiring easily obtainable local information. Thus, it clearly makes sense to use the
square-root topology instead of constant degree or proportional topologies.
A widely used topology in many systems is the super-peer topology. In this topology, a fraction of the
peers serve as super-peers, aggregating content information from several “leaf” pears. Then, searches only need
to be sent to super-peers. The superpeers are connected using a normal unstructured topology. We ran
simulations using a standard superpeer topology, in which searches are flooded to super peers.We compared this
standard topology to a super peer topology that used the square-root topology and random walks between super
peers. The results indicate a significant improvement using our techniques: the square root super peer network
required 54 percent fewer messages than a standard super-peer network.
IV. Conclusions
We compares structured and unstructured overlays, demonstrating through analytical and simulation
results how an unstructured solution relying on a scale-free topology is an effective option to deploy for offering
services based on equivalent servants. On the basis of this result, The EQUivalent servAnt locaTOR
(EQUATOR) architecture, which overcomes the issues related to the deployment of a scale-free topology for
service location in a real network, mainly due to the static nature of the ideal scale-free construction algorithm
and the lack of a global knowledge of the participating peers. Simulation results confirmed the effectiveness of
EQUATOR, showing how it offers good lookup performance in conjunction with low message overhead and
high resiliency to node churn and failures. Some possible future works are introduced and are related to some
complementary issues ranging from the proximity-aware selection of servants to the introduction of proper
incentives to encourage nodes to join the EQUATOR overlay and offer their resources.
Peer-to-peer computing takes advantage of existing desktop computing power and networking connectivity,
allowing economical clients to leverage their collective power to benefit the entire enterprise
Large number of participating servants and user’s single entity directly handles all possible servants and
consequently offers the best performance
6. Scale-Free Networks to Search in Unstructured Peer-To-Peer Networks
www.iosrjournals.org 17 | Page
References
[1]. Q.Lv ,P.Cao, E.Cohen, K.Li, and S. Shenker, “Search and replication in unstructured peer-to-peer networks,” SIGMETRICS Perform.
Eval. Rev., vol. 30, no. 1, pp. 258–259, 2002.
[2]. R. Albert and A.-L. Barabási, “Statistical mechanics of complex networks,” Rev. Mod. Phys., vol. 74, pp. 47–97, Jan. 2002.
[3]. L. A. Adamic, R. M. Lukose, A. R. Puniyani, and B. A. Huberman, “Search in power-law networks,” Phys. Rev. E, vol. 64, no. 4, pp.
Sep 2001.
[4]. Guido Marchetto, Luigi Ciminiera, Marco Papa Manzillo, Fulvio Risso, Livio Torrero, “Locating Equivalent Servants over P2P
Networks”
[5]. Oliver Hein, Michael Schwind, Wolfgang Konig, “Scale-Free Networks” The Impact of Fat Tailed Degree Distribution on Diffusion
and Communication Processes.
[6]. Barabasi, Albert-Laszlo; Albert, Reka: Emergence of Scaling in Random Networks. In: Science 286 (1999), pp. 509–512.
[7]. Barabasi, Albert-Laszlo; Bonabeau, Eric: Scale-Free Networks. Scientific American 2003.
[8]. Ebel, H.; Mielsch, L.-I.; Bornholdt., S.: Scale-free topology of e-mail networks. In: Phys. Rev. E 66 (2002), pp. 035103.