12/7/23, 7:38 PM
`
`Peer-to-peer interactions in web brokering systems
`
`Articles
`PEER-TO-PEER INTERACTIONS IN WEB
`BROKERING SYSTEMS
`Ubiquity, Volume 2002 Issue May, May 1- May 31, 2002 | BY GEOFFREY FOX
`, SHRIDEEP PALLICKARA
`
`| F
`
`ull citation in the ACM Digital Library
`
`Global structure and local dynamic messaging support a wide range of
`applications
`
`The peer-to-peer (P2P) style interaction model facilitates sophisticated
`resource sharing environments between "consenting" peers over the "edges"
`of the Internet; the "disruptive" impact of which has resulted in a slew of
`powerful applications built around this model. Resources shared could be
`anything from CPU cycles, exemplified by SETI@home (extraterrestrial life)
`and Folding@home (protein folding), to files (Napster and Gnutella). Peer
`"interactions" involves advertising resources, search and subsequent
`discovery of resources, requests for access to these resources, responses to
`these requests and exchange of messages between peers.
`
`Since peer interactions, in most P2P systems, are XML-based, peers could
`be written in any language and can be compiled for any platform. Driven
`entirely on demand a resource may be replicated several times; a process
`that is decentralized and one over which the original peer that advertised the
`resource has sometimes little control over. The greater the demand for a
`resource, the greater the system initiated replications for the resource,
`resulting in fewer bottlenecks and faster accesses to that resource.
`
`Services proliferating the Internet can be abstracted as a distributed system
`of "clients" comprising "users," "resources" or proxies thereto. These Web
`services are usually hosted on a "broker" or a network of brokers, where the
`term server is avoided to distinguish it clearly from application servers.
`Clients access Web services by connecting to a broker, where the client's
`online presence is neither time constrained nor is it tied to a specific device,
`geographic location or communication channel. Clients then maintain active
`connections to the hosting broker throughout the duration that they use the
`service.
`
`Integrating support for P2P systems, such as Sun Microsystems' JXTA (from
`juxtaposition), within the brokering framework have several benefits that can
`be accrued by both systems. This integration would allow Web-brokering
`systems to leverage P2P interactions and applications while providing peers
`access to legacy systems. Intelligent routing of P2P interactions, which would
`be accorded to peers in the integrated system, would result in improved
`latencies at peers and efficient overall network usage. Furthermore, the
`integrated system would enable the development of "hybrid-clients" and
`applications that could utilize features derived from these different
`frameworks. In such integrated systems not every hybrid-client interaction
`needs to be funneled through the broker network since such hybrid-clients
`can sometimes service each other's requests while peer accesses to shared
`resources can be reliable and error-free. Support for other messaging
`frameworks such as the Java Message Service (JMS) within the brokering
`system and bridges to, and from, other P2P systems would facilitate the
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`Dropbox Exhibit 1022 - Page 1
`Dropbox, Inc. v. Entangled Media, LLC
`IPR2024-00285 - U.S. Patent No. 8,484,260
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`12/7/23, 7:38 PM
`efficient development of rich complex applications.
`
`Peer-to-peer interactions in web brokering systems
`
`In traditional brokering systems the request/response model is fixed (one
`response for a request) with the client initiating the request having no
`ambiguity on how the request would be interpreted while also being aware of
`the template that the response would conform to. In contrast, in P2P
`systems, not every request goes through, and even if it does, there could be
`zero or more valid responses. Peers anticipate neither the template that the
`responses would conform to nor the order in which these responses would
`be received. Furthermore, responses are not identical with each responding
`peer processing any given request based on the resources at its disposal
`and its interpretation of the request. Communication between a requesting
`peer and responding peers is facilitated by peers en route to these
`destinations. These intermediate peers are thus made aware of capabilities
`that exist at other peers. This discovery of services offered by other peers
`constitutes dynamic real time knowledge propagation. Peer requests are
`sometimes satisfied through cached responses, and peers generally have a
`choice on whether to accept these cached responses or not. It's up to the
`peer to discard responses that it deems are not correct.
`
`P2P interactions are self-attenuating with interactions dying out after a
`certain number of hops. These attenuations in tandem with traces of the
`peers, which the interactions have passed through, eliminate the continuous
`echoing problem that results from loops in peer connectivity. However,
`attenuation of interactions sometimes prevents clients from discovering
`certain services being offered. Peers hosting these services could not
`respond because the request attenuated before it could have reached the
`hosting peer. This results in P2P interactions being very localized. Of course,
`if the peer at the edge of the attenuation had cached the response or the
`resource itself, for a similar request that it made at an earlier time, that
`particular peer can respond to the requesting peer. Unlike clients in Web
`brokering systems that interact via the broker network, peers in P2P systems
`interact directly with each other and sometimes use other peers as
`intermediaries in interactions. Specialized peers are sometimes deployed to
`enhance routing characteristics. Nevertheless, sophisticated routing
`schemes are seldom in place and interactions are primarily through simple
`forwarding of requests with the propagation range being determined by the
`attenuation indicated in the message.
`
`The aforementioned issues of discovery of services and intelligent routing
`can be addressed very well in distributed brokering systems. Single broker
`solutions would entail P2P interactions being funneled through the lone
`broker leading to bottlenecks. The associated drawbacks in scaling,
`increased latencies due to queuing delays and the single point of failure that
`such a scheme constitutes are among the reasons favoring a distributed
`model being in place. Strategies for integrating P2P interactions need to
`ensure that minimal changes need to be made to the brokering core.
`Furthermore, this integration should entail neither any changes to the peers
`nor a straitjacketing of the interactions that these peers could have had prior
`to the integration. A solution to this problem is via P2P-proxies, which would
`provide an interconnection bridge between the two systems. The P2P-
`proxies are part routing peers and part clients of the Web brokering system.
`Peers would interact with the P2P-proxies as they would with any other peer,
`while the P2P-proxy inherits guarantees accorded to clients of the brokering
`system. Since every P2P-proxy is treated as a peer by the other peers it is
`part of the communication and dynamic discovery schemes associated with
`original peers. In its dual role as a client of the brokering system, the P2P-
`proxy forwards these interactions to the broker that it is attached to in order
`to aid in their efficient disseminations. This strategy involves no changes to
`peers neither does it entail major changes within the existing distributed
`broker network. The broker network would be used primarily as a delivery
`engine, and a pretty efficient one at that, while locating peers and
`propagating interactions to relevant peers.
`
`The most important aspect in P2P systems is the satisfaction of peer
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`Dropbox Exhibit 1022 - Page 2
`Dropbox, Inc. v. Entangled Media, LLC
`IPR2024-00285 - U.S. Patent No. 8,484,260
`
`

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`Peer-to-peer interactions in web brokering systems
`12/7/23, 7:38 PM
`requests and discovery of peers and associated resources that could handle
`these requests. The broker network needs to forward these requests only to
`those peers that it believes can handle the requests. Peer interactions in
`most P2P systems are achieved through XML-based data interchange.
`XML's data description and encapsulation properties allow for ease of
`accessing specific elements of data. Individual brokers routing interactions
`could access relevant elements, cache this information and use it
`subsequently to achieve the best possible routing characteristics. Routing for
`P2P interactions can be optimized since individual brokers, being aware of
`interconnectivities within the broker network, the broker topology and
`individual client/peer interests; would arrive at routing decisions to ensure
`that the events would be routed to the P2P-proxies best suited to handle the
`P2P interaction. These P2P-proxies would then locate peers that would
`service the request or the peer that the response was intended for or peers
`that are en route to the destination peer(s). The brokering system, since it is
`aware of advertisements, can also act as a hub for search and discovery
`operations. These advertisements when organized into "queryspaces" allow
`the integrated system to respond to search operations more efficiently.
`
`Resources in Web brokering systems are generally within the purview of the
`broker network. P2P systems replicate resources in an ad hoc fashion, the
`availability of which is dependent on the peer's active digital presence. Some
`resources, however, are best managed by the brokering system rather than
`being left to the discretion of peers who may or may not be present at any
`given time. An understanding of the network topology and an ability to
`pinpoint the existence of peers interested in that resource are paramount to
`efficient replications of a resource. The distributed broker network,
`possessing this knowledge, best handles this management of resources
`while ensuring that these replicated resources are "closer" and "available" at
`locations with a high interest in that resource. Furthermore, the broker
`network is also better suited, than a collection of peers, to eliminate race
`conditions and deadlocks that could exist due to a resource being accessed
`simultaneously by multiple peers. Broker networks can be responsive to
`changes in peer concentrations, volumes of peer requests, and resource
`availability. Brokers and associated interconnections can be dynamically
`instantiated or purged to compensate for affected routing characteristics due
`to changes in peer interactions.
`
`The integrated system could also be used to connect islands of peers
`together. Peers that are not directly connected through the peer network
`could be indirectly connected through the broker network. Peer interactions
`and resources in the P2P model are traditionally unreliable, with interactions
`being lost or discarded due to peer failures or absences, overloading of
`peers and queuing thresholds being reached. Guaranteed delivery properties
`existing in traditional brokering systems can augment peer behavior to
`provide a notion of reliable peers, interactions and resources.
`
`Such an integrated brokering solution would also allow for hybrid interaction
`schemes to exist alongside each other. Applications could be built around
`hybrid-clients that would exhibit part peer behavior and part traditional client
`behavior. P2P communications could be used for traffic where loss of
`information can be sustained. Similarly, hybrid-clients needing to
`communicate with each other in a "reliable" fashion could utilize the
`brokering system's capabilities to achieve that. Sometimes, hybrid-clients can
`satisfy each other's requests, in which case they would, obviating need for
`funneling interactions through the broker network. The broker merely serves
`as an efficient conduit for supporting interaction between different
`applications (clients, peers or hybrid).
`
`A typical application of this integrated solution is distance education. This
`often consists of multiple linked classrooms where the participants in each
`classroom are individually linked to collaborative environment. Here a peer-
`to-peer model can be used in a classroom to give fast dynamic response to
`shared input control while the guaranteed delivery capability is used to
`multicast between classrooms. More generally this combination of global
`
`https://ubiquity.acm.org/article.cfm?id=544731
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`3/4
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`Dropbox Exhibit 1022 - Page 3
`Dropbox, Inc. v. Entangled Media, LLC
`IPR2024-00285 - U.S. Patent No. 8,484,260
`
`

`

`Peer-to-peer interactions in web brokering systems
`12/7/23, 7:38 PM
`structured and local dynamic messaging scales to support a wide range of
`applications.
`
`Geoffrey Fox is a professor in the Departments of Computer Science and
`Physics at Indiana University. Shrideep Pallickara is a post doctoral fellow in
`the Computer Science Department at Indiana University. The research
`prototype of the strategy outlined in the article is available at
`http://grids.ucs.indiana.edu/ptliupages/projects/narada/.
`
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`4/4
`
`Dropbox Exhibit 1022 - Page 4
`Dropbox, Inc. v. Entangled Media, LLC
`IPR2024-00285 - U.S. Patent No. 8,484,260
`
`