| 1. |
- Constantinescu, Doru, et al.
(författare)
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Congestion and Error Control in Overlay Networks
- 2007
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- In recent years, Internet has known an unprecedented growth, which, in turn, has lead to an increased demand for real-time and multimedia applications that have high Quality-of-Service (QoS) demands. This evolution lead to difficult challenges for the Internet Service Providers (ISPs) to provide good QoS for their clients as well as for the ability to provide differentiated service subscriptions for those clients who are willing to pay more for value added services. Furthermore, a tremendous development of several types of overlay networks have recently emerged in the Internet. Overlay networks can be viewed as networks operating at an inter-domain level. The overlay hosts learn of each other and form loosely-coupled peer relationships. The major advantage of overlay networks is their ability to establish subsidiary topologies on top of the underlying network infrastructure acting as brokers between an application and the required network connectivity. Moreover, new services that cannot be implemented (or are not yet supported) in the existing network infrastructure are much easier to deploy in overlay networks. In this context, multicast overlay services have become a feasible solution for applications and services that need (or benefit from) multicast-based functionality. Nevertheless, multicast overlay networks need to address several issues related to efficient and scalable congestion control schemes to attain a widespread deployment and acceptance from both end-users and various service providers. This report aims at presenting an overview and taxonomy of current solutions proposed that provide congestion control in overlay multicast environments. The report describes several protocols and algorithms that are able to offer a reliable communication paradigm in unicast, multicast as well as multicast overlay environments. Further, several error control techniques and mechanisms operating in these environments are also presented. In addition, this report forms the basis for further research work on reliable and QoS-aware multicast overlay networks. The research work is part of a bigger research project, "Routing in Overlay Networks (ROVER)". The ROVER project was granted in 2006 by EuroNGI Network of Excellence (NoE) to the Dept. of Telecommunication Systems at Blekinge Institute of Technology (BTH).
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| 2. |
- Erman, David, et al.
(författare)
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BitTorrent Session Characteristics and Models : Extended Version
- 2009
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Ingår i: Traffic and Performance Engineering for Heterogeneous Networks. - : River Publishers. - 9788792329165
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Bokkapitel (refereegranskat)abstract
- This paper reports on a modeling and evaluation study of session characteristics of Bit- Torrent traffic. BitTorrent is a second generation Peer-to-Peer (P2P) application recently developed as an alternative to the classical client-server model to reduce the load burden on content servers and networks. Results are reported on measuring, modeling and analy- sis of application layer traces collected at the Blekinge Institute of Technology (BTH) and at a local Internet Service Provider (ISP). For doing this, a measurement infrastructure has been developed at BTH to collect P2P traffic. A dedicated modeling methodology has been put forth as well. New results are reported on session characteristics of BitTorrent, and it is observed that session interarrival times can be accurately modeled by the hyper- exponential distribution while session durations and sizes can be reasonably well modeled by the lognormal distribution.
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| 3. |
- Erman, David, et al.
(författare)
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BitTorrent Session Characteristics and Models
- 2005
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Konferensbidrag (refereegranskat)abstract
- The paper reports on a modeling and evaluation study of session characteristics of BitTorrent traffic. BitTorrent is a second generation Peer-to-Peer (P2P) application recently developed as an alternative to the classical client-server model to reduce the load burden on content servers and networks. Results are reported on measuring, modeling and analysis of application layer traces collected at the Blekinge Institute of Technology (BIT) and a local ISP. For doing this, a dedicated measurement infrastructure has been developed at BIT to collect P2P traffic. A dedicated modeling methodology has been put forth as well. New results are reported on session characteristics of BitTorrent, and it is observed that session interarrivals can be accurately modeled by the hyper-exponential distribution while session durations and sizes can be reasonably well modeled by the lognormal distribution.
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| 4. |
- Erman, David, et al.
(författare)
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BitTorrent Traffic Characteristics
- 2006
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Konferensbidrag (refereegranskat)abstract
- This paper reports on a measurement and modeling study of session and message characteristics of BitTorrent traffic. BitTorrent is a Peer-to-peer (P2P) replication and distribution system developed as an alternative to the classical client-server model to reduce the load on content servers and networks. Results are reported on measurement, modeling and analysis of application and link layer traces collected at the Blekinge Institute of Technology (BTH) and a local ISP in Sweden. Link layer traces and application logs were collected, modeled and analyzed using a dedicated measurement infrastructure developed at BTH to collect P2P traffic. New results are reported on important session and message characteristics of BitTorrent, i.e., session interarrivals, sizes and durations, request rates and response times. Our results show that session interarrivals can be accurately modeled by a second-order hyper-exponential distribution while session durations and sizes can be reasonably well modeled by various mixtures of the Log-normal and Weibull distributions. Response times have been observed to be modeled by a dual Log-normal mixture, while request rates are modeled as dual Gaussian distributions.
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| 5. |
- Erman, David, et al.
(författare)
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Measurement and Analysis of BitTorrent Signaling Traffic
- 2004
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Konferensbidrag (refereegranskat)abstract
- BitTorrent is a second generation Peer-to-Peer application that has been recently developed as an alternative to the classical client-server model to reduce the load burden on content servers and networks. The protocol relies on the use of swarming techniques for distributing content. No search functionality is built into the protocol, and the signaling is geared only towards an efficient dissemination of data. The paper reports on measurement and analysis of BitTorrent traffic collected at the Blekinge Institute of Technology (BIT), Karlskrona, Sweden. We measure and analyze data from local BitTorrent client sessions at BIT. The characteristics of the signaling traffic exchanged among the participating peers in a BitTorrent distribution swarm are investigated. A dedicated approach based on combining instrumentation at the application layer with flow identification and extraction at the transport layer is used for traffic measurements.
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| 6. |
- Erman, David, et al.
(författare)
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Measuring and Modeling the BitTorrent Content Distribution System
- 2010
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Ingår i: Computer Communications. - : Elsevier. - 0140-3664 .- 1873-703X. ; 33:Sp. Iss. SI Suppl. 1, s. S22-S29
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Tidskriftsartikel (refereegranskat)abstract
- The paper reports on a detailed study of the BitTorrent content distribution system. We first present a measurement infrastructure designed to allow detailed, message-level capture and analysis of P2P traffic. An associated modeling methodology is presented as well. These tools have been used to measure and model the BitTorrent protocol, which is observed to exhibit exponential characteristics of session interarrival times. We also observe that session durations and sizes are modeled with a lognormal distribution.
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| 7. |
- Ilie, Dragos, et al.
(författare)
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A Framework for Overlay QoS Routing
- 2007
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- The emergence of new types of popular multimedia services requires in the long run a quality-of-service (QoS) solution better than the best-effort service provided by IP. Failure to widely deploy either one of the main architectures for IP QoS, integrated services (IntServ) or differentiated services (DiffServ), has fueled research into alternate solutions based on overlay networks on top of IP. At Blekinge Institute of Technology (BTH) we are working towards an architecture for multimedia distribution in overlay networks. An important part of this architecture is QoS overlay routing. This paper discusses Overlay Routing protocol (ORP), a framework for unicast overlay routing, which will be used to test various QoS routing protocols and algorithms.
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| 8. |
- Ilie, Dragos, et al.
(författare)
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Measurement and Analysis of Gnutella Signaling Traffic
- 2004
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Konferensbidrag (refereegranskat)abstract
- The paper reports on in-depth measurements and analysis of Gnutella signaling traffic collected at the Blekinge Institute of Technology (BIT), Karlskrona, Sweden. The measurements are based on a week-long packet trace collected with help of the well-known tcpdump application. Furthermore, a novel approach has been used to measure and analyze Gnutella signaling traffic. Associated with this, a dedicated tcptrace module has been developed and used to decode the packet trace, down to individual Gnutella messages. The measurement infrastructure consists of a Gnutella node running in ultrapeer mode and protocol decoding software. Detailed traffic characteristics have been collected and analyzed, such as session durations and interarrival times, and Gnutella message sizes and duration. Preliminary results show a high degree of variability of the Gnutella signaling traffic, which is mostly created by the QUERY messages. Furthermore, the Gnutella session interarrival times are observed to resemble the exponential distribution.
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| 9. |
- Ilie, Dragos, et al.
(författare)
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Statistical Models for Gnutella Signaling Traffic
- 2007
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Ingår i: Computer Networks. - Amsterdam : ScienceDirect. - 1389-1286 .- 1872-7069. ; 51:17, s. 4816-4835
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Tidskriftsartikel (refereegranskat)abstract
- The paper is focused on signaling traffic between Gnutella peers that implement the latest Gnutella protocol specifications (v0.6). In particular, we provide analytically tractable statistical models at session level, message level and IP datagram level for traffic crossing a Gnutella ultrapeer at Blekinge Institute of Technology (BTH) in Karlskrona, Sweden. To the best of our knowledge this is the first work that provides Gnutella v0.6 statistical models at this level of detail. These models can be implemented straightforward in network simulators such as ns2 and OmNet++. The results show that incoming requests to open a session follow a Poisson distribution. Incoming Gnutella messages across all established sessions can be described by a compound Poisson distribution. Mixture distribution models for message transfer rates include a heavy-tailed component.
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| 10. |
- Ilie, Dragos, et al.
(författare)
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Traffic Measurements of P2P Systems
- 2004
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Konferensbidrag (refereegranskat)abstract
- The paper reports on a measurement infrastructure developed at the Blekinge Institute of Technology (BIT) with the purpose to do traffic measurements and analysis on Peer-to-Peer (P2P) traffic. The measurement methodology is based on using application logging as well as link-layer packet capture. This offers the possibility to measure application layer information with link-layer accuracy. Details are reported on this methodology, together with description of the BIT measurement infrastructure. The paper also reports on traffic measurements done on BitTorrent and Gnutella protocols from an end-client perspective, together with some measurement results of salient protocol characteristics. Preliminary results show a high degree of variability of the BitTorrent and Gnutella traffic, where in the case of Gnutella a large contribution is given by the signaling traffic.
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