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Peer-to -Peer Net Works
Published in Giovanni Bartolomeo, Tatiana Kováčiková, Identification and Management of Distributed Data: NGN, Content-Centric Networks and the Web, 2016
Giovanni Bartolomeo, Tatiana Kováčiková
The Gnutella network adopts an approach based on broadcasting. Gnutella “servants” join the Gnutella network by contacting host cache servers, prominent network nodes whose function is to cache the IP address of the contacting node. This approach both provides the joining node with a list of servants already in the network and caches the address of the new node, which is likely to become a servant. Once the new node is connected to at least one node of the Gnutella network, it can forward discovery messages to find additional nodes and establish connections with them, using a TCP-based protocol. Outgoing messages contain a time-to-live (TTL) field. Peers receiving the message forward it to other peers with whom they are connected (avoiding loops). The TTL is decreased at each hop. Messages whose TTL is zero are discarded to avoid flooding the network. Table 10.1 illustrates the different kinds of messages used in Gnutella. Ping and pong messages are used to discover other peers, whereas query and query hit messages lookup content. Once content is found, the requesting node establishes a Hypertext Transfer Protocol (HTTP) connection to the servant where the content is located and downloads the file. Download of one or more subranges (in terms of bytes) of the requested resource instead of the whole content can be interrupted and resumed using the HTTP Range request-header field.
Key nodes mining for complex networks based on local gravity model
Published in Journal of Control and Decision, 2023
Tao Ren, Shixiang Sun, Yanjie Xu, Georgi Marko Dimirovski
Jazz (Gleiser & Danon, 2003) is a cooperative network of jazz musicians. The nodes in the network are musicians, and the links between nodes are the cooperative relationship between musicians. NS (Newman, 2006) is a co-authored network composed of scholars engaged in network science research. Email (Guimerà et al., 2003) describes the Email interaction between various types of personnel at Rovira i Virgili University. PG (Leskovec et al., 2007) is a snapshot of the Gnutella peer-to-peer file-sharing network from August 2002. Enron (Leskovec et al., 2009) is the Enron email network. PB (Adamic & Glance, 2005) is a network of US political blogs. Facebook (Mcauley & Leskovec, 2012) describes social circles from the celebrated Facebook. WV (Leskovec et al., 2010) is a network of Wikipedia who-votes-on-whom. Sex (Rocha et al., 2011) is a bipartite network in which nodes are females (sex sellers) and males (sex buyers) and links between them are established when males write posts indicating sexual encounters with females. USAir (Batageli & Mrvar, 2007) is the airport transportation network of the United States. In Table 1, the network statistical features of above-mentioned networks are shown. Where is the number of nodes, is the number of edges, represents the average degree of the network, denotes the average path length, is the clustering coefficient and is the propagation threshold of the corresponding SIR mode.