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JXTA
JXTA (Juxtapose) was an open-source peer-to-peer protocol specification begun by Sun Microsystems in 2001. The JXTA protocols were defined as a set of XML messages which allow any device connected to a network to exchange messages and collaborate independently of the underlying network topology. As JXTA was based upon a set of open XML protocols, it could be implemented in any modern computer language. Implementations were developed for Java SE, C/C++, C# and Java ME. The C# Version used the C++/ C native bindings and was not a complete re-implementation in its own right. JXTA peers create a virtual overlay network which allows a peer to interact with other peers even when some of the peers and resources are behind firewalls and NATs or use different network transports. In addition, each resource is identified by a unique ID, a 160 bit SHA-1 URN in the Java binding, so that a peer can change its localization address while keeping a constant identification number. Status ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Overlay Network
An overlay network is a computer network that is layered on top of another network. Structure Nodes in the overlay network can be thought of as being connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network. For example, distributed systems such as peer-to-peer networks and client–server applications are overlay networks because their nodes run on top of the Internet. The Internet was originally built as an overlay upon the telephone network, while today (through the advent of VoIP), the telephone network is increasingly turning into an overlay network built on top of the Internet. Uses Enterprise networks Enterprise private networks were first overlaid on telecommunication networks such as Frame Relay and Asynchronous Transfer Mode packet switching infrastructures but migration from these (now legacy) infrastructures to IP based MPLS networks and virtual private networks started (2001~ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rendezvous Protocol
A rendezvous protocol is a computer network protocol that enables resources or P2P network peers to find each other. A rendezvous protocol uses a handshaking model, unlike an eager protocol which directly copies the data. In a rendezvous protocol the data is sent when the destination says it is ready, but in an eager protocol the data is sent assuming the destination can store the data. Examples of rendezvous protocols include JXTA, SIP, Freenet Project, I2P, and such protocols generally involve hole punching. Because of firewall network address translation (NAT) issues, rendezvous protocols generally require that there be at least one unblocked and un-NATed server that lets the peers locate each other and initiate concurrent packet Packet may refer to: * A small container or pouch ** Packet (container), a small single use container ** Cigarette packet ** Sugar packet * Network packet, a formatted unit of data carried by a packet-mode computer network * Packet radio, a for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Distributed Hash Table
A distributed hash table (DHT) is a distributed system that provides a lookup service similar to a hash table: key–value pairs are stored in a DHT, and any participating node can efficiently retrieve the value associated with a given key. The main advantage of a DHT is that nodes can be added or removed with minimum work around re-distributing keys. ''Keys'' are unique identifiers which map to particular ''values'', which in turn can be anything from addresses, to documents, to arbitrary data. Responsibility for maintaining the mapping from keys to values is distributed among the nodes, in such a way that a change in the set of participants causes a minimal amount of disruption. This allows a DHT to scale to extremely large numbers of nodes and to handle continual node arrivals, departures, and failures. DHTs form an infrastructure that can be used to build more complex services, such as anycast, cooperative web caching, distributed file systems, domain name services, instant ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peer-to-peer
Peer-to-peer (P2P) computing or networking is a distributed application architecture that partitions tasks or workloads between peers. Peers are equally privileged, equipotent participants in the network. They are said to form a peer-to-peer network of nodes. Peers make a portion of their resources, such as processing power, disk storage or network bandwidth, directly available to other network participants, without the need for central coordination by servers or stable hosts. Peers are both suppliers and consumers of resources, in contrast to the traditional client–server model in which the consumption and supply of resources are divided. While P2P systems had previously been used in many application domains, the architecture was popularized by the file sharing system Napster, originally released in 1999. The concept has inspired new structures and philosophies in many areas of human interaction. In such social contexts, peer-to-peer as a meme refers to the egalitarian so ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peer-to-peer
Peer-to-peer (P2P) computing or networking is a distributed application architecture that partitions tasks or workloads between peers. Peers are equally privileged, equipotent participants in the network. They are said to form a peer-to-peer network of nodes. Peers make a portion of their resources, such as processing power, disk storage or network bandwidth, directly available to other network participants, without the need for central coordination by servers or stable hosts. Peers are both suppliers and consumers of resources, in contrast to the traditional client–server model in which the consumption and supply of resources are divided. While P2P systems had previously been used in many application domains, the architecture was popularized by the file sharing system Napster, originally released in 1999. The concept has inspired new structures and philosophies in many areas of human interaction. In such social contexts, peer-to-peer as a meme refers to the egalitarian so ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Distributed Data Storage
A distributed data store is a computer network where information is stored on more than one node, often in a replicated fashion. It is usually specifically used to refer to either a distributed database where users store information on a ''number of nodes'', or a computer network in which users store information on a ''number of peer network nodes''. Distributed databases Distributed databases are usually non-relational databases that enable a quick access to data over a large number of nodes. Some distributed databases expose rich query abilities while others are limited to a key-value store semantics. Examples of limited distributed databases are Google's Bigtable, which is much more than a distributed file system or a peer-to-peer network, Amazon's Dynamo and Microsoft Azure Storage. As the ability of arbitrary querying is not as important as the availability, designers of distributed data stores have increased the latter at an expense of consistency. But the high-speed r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chimera (software Library)
Chimera is a software library created as a research project at UCSB for the C programming language that implements a structured, peer-to-peer routing platform to allow the easy development of peer-to-peer applications. The project's focus is on providing a fast, lightweight implementation of a system like other prefix-routing protocols such as UCSB's Tapestry system and Microsoft Research's Pastry system, that can be easily used to build an application that creates an overlay network with a limited number of library calls. The library is intended to serve as both a usable complete structured peer-to-peer system and a starting point for further research. It includes some of the current work in locality optimization and soft-state operations. The system contains both a leaf set of ''neighbor nodes'', which provides fault tolerance and a probabilistic invariant of constant routing progress, and a PRR-style routing table to improve routing time to a logarithmic factor of network size. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Churn Rate
Churn rate (sometimes called attrition rate), in its broadest sense, is a measure of the number of individuals or items moving out of a collective group over a specific period. It is one of two primary factors that determine the Steady state, steady-state level of customers a business will support. Derived from the butter churn, the term is used in many contexts but most widely applied in business with respect to a contractual customer base. Examples include a Subscription business model, subscriber-based service model as used by mobile telephone networks and pay TV operators. The term is often synonymous with Turnover (other), turnover, for example participant turnover in peer-to-peer networks. Churn rate is an input into customer lifetime value modeling, and can be part of a simulator used to measure return on marketing investment using marketing mix modeling. Customer base churn Churn rate, when applied to a customer base, refers to the proportion of contractual custom ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Unicast
Unicast is data transmission from a single sender (red) to a single receiver (green). Other devices on the network (yellow) do not participate in the communication. In computer networking, unicast is a one-to-one transmission from one point in the network to another point; that is, one sender and one receiver, each identified by a network address. Unicast is in contrast to multicast and broadcast which are one-to-many transmissions. Internet Protocol unicast delivery methods such as Transmission Control Protocol (TCP) and User Datagram Protocol (UDP) are typically used. See also * Anycast * Broadcast, unknown-unicast and multicast traffic * IP address * IP multicast * Routing Routing is the process of selecting a path for traffic in a network or between or across multiple networks. Broadly, routing is performed in many types of networks, including circuit-switched networks, such as the public switched telephone netw ... References External links * * Internet archit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Communication Channel
A communication channel refers either to a physical transmission medium such as a wire, or to a logical connection over a multiplexed medium such as a radio channel in telecommunications and computer networking. A channel is used for information transfer of, for example, a digital bit stream, from one or several '' senders'' to one or several '' receivers''. A channel has a certain capacity for transmitting information, often measured by its bandwidth in Hz or its data rate in bits per second. Communicating an information signal across distance requires some form of pathway or medium. These pathways, called communication channels, use two types of media: Transmission line (e.g. twisted-pair, coaxial, and fiber-optic cable) and broadcast (e.g. microwave, satellite, radio, and infrared). In information theory, a channel refers to a theoretical ''channel model'' with certain error characteristics. In this more general view, a storage device is also a communication channel, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HTTP
The Hypertext Transfer Protocol (HTTP) is an application layer protocol in the Internet protocol suite model for distributed, collaborative, hypermedia information systems. HTTP is the foundation of data communication for the World Wide Web, where hypertext documents include hyperlinks to other resources that the user can easily access, for example by a mouse click or by tapping the screen in a web browser. Development of HTTP was initiated by Tim Berners-Lee at CERN in 1989 and summarized in a simple document describing the behavior of a client and a server using the first HTTP protocol version that was named 0.9. That first version of HTTP protocol soon evolved into a more elaborated version that was the first draft toward a far future version 1.0. Development of early HTTP Requests for Comments (RFCs) started a few years later and it was a coordinated effort by the Internet Engineering Task Force (IETF) and the World Wide Web Consortium (W3C), with work later moving to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
