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Virtual network

About: Virtual network is a research topic. Over the lifetime, 8795 publications have been published within this topic receiving 116758 citations.


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Patent
05 Jun 2013
TL;DR: In this paper, a distributed virtual network controller is described that configures and manages an overlay network within a physical network formed by plurality of switches, each of the servers comprising an operating environment executing one or more virtual machines in communication via the overlay networks.
Abstract: In general, techniques are described for configuring and managing virtual networks. For example, a distributed virtual network controller is described that configures and manages an overlay network within a physical network formed by plurality of switches. A plurality of servers are interconnected by the switch fabric, each of the servers comprising an operating environment executing one or more virtual machines in communication via the overlay networks. The servers comprises a set of virtual switches that extends the overlay network as a virtual network to the operating environment of the virtual machines. The controller may instruct the servers and the virtual switches to perform various operations, such as determining a physical network path taken by packets of a network packet flow, determining latency through the network, re-routing traffic in the virtual network due to network events, replicating traffic for multicasting, providing multi-tenant services to support multiple virtual networks, monitoring and logging traffic characteristics within the virtual networks and other operations.

515 citations

Proceedings ArticleDOI
24 Aug 2015
TL;DR: A thorough study of the NFV location problem is performed, it is shown that it introduces a new type of optimization problems, and near optimal approximation algorithms guaranteeing a placement with theoretically proven performance are provided.
Abstract: Network Function Virtualization (NFV) is a new networking paradigm where network functions are executed on commodity servers located in small cloud nodes distributed across the network, and where software defined mechanisms are used to control the network flows. This paradigm is a major turning point in the evolution of networking, as it introduces high expectations for enhanced economical network services, as well as major technical challenges. In this paper, we address one of the main technical challenges in this domain: the actual placement of the virtual functions within the physical network. This placement has a critical impact on the performance of the network, as well as on its reliability and operation cost. We perform a thorough study of the NFV location problem, show that it introduces a new type of optimization problems, and provide near optimal approximation algorithms guaranteeing a placement with theoretically proven performance. The performance of the solution is evaluated with respect to two measures: the distance cost between the clients and the virtual functions by which they are served, as well as the setup costs of these functions. We provide bi-criteria solutions reaching constant approximation factors with respect to the overall performance, and adhering to the capacity constraints of the networking infrastructure by a constant factor as well. Finally, using extensive simulations, we show that the proposed algorithms perform well in many realistic scenarios.

509 citations

Proceedings ArticleDOI
17 Aug 2009
TL;DR: A Virtual Network Mapping (VNM) algorithm based on subgraph isomorphism detection: it maps nodes and links during the same stage and is faster than the two stage approach, especially for large virtual networks with high resource consumption which are hard to map.
Abstract: Assigning the resources of a virtual network to the components of a physical network, called Virtual Network Mapping, plays a central role in network virtualization. Existing approaches use classical heuristics like simulated annealing or attempt a two stage solution by solving the node mapping in a first stage and doing the link mapping in a second stage.The contribution of this paper is a Virtual Network Mapping (VNM) algorithm based on subgraph isomorphism detection: it maps nodes and links during the same stage. Our experimental evaluations show that this method results in better mappings and is faster than the two stage approach, especially for large virtual networks with high resource consumption which are hard to map.

502 citations

Posted Content
TL;DR: In this paper, the authors analyze the topology graph of Gnutella's application level network and evaluate generated network traffic, finding that the current configuration has the benefits and drawbacks of a power-law structure.
Abstract: Despite recent excitement generated by the peer-to-peer (P2P) paradigm and the surprisingly rapid deployment of some P2P applications, there are few quantitative evaluations of P2P systems behavior. The open architecture, achieved scale, and self-organizing structure of the Gnutella network make it an interesting P2P architecture to study. Like most other P2P applications, Gnutella builds, 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 scalability. We have built a "crawler" to extract the topology of Gnutella's application level network. In this paper we analyze the topology graph and evaluate generated network traffic. Our two major findings are that: (1) although Gnutella is not a pure power-law network, its current configuration has the benefits and drawbacks of a power-law structure, and (2) the Gnutella virtual network topology does not match well the underlying Internet topology, hence leading to ineffective use of the physical networking infrastructure. These findings guide us to propose changes to the Gnutella protocol and implementations that may bring significant performance and scalability improvements. We believe that our findings as well as our measurement and analysis techniques have broad applicability to P2P systems and provide unique insights into P2P system design tradeoffs.

476 citations

Journal ArticleDOI
TL;DR: Averaging over many configurations of perturbed electrical network, results point to a sizeable amplification of the effects of faults on the electrical network on the communication network, also in the case of a moderate coupling between the two networks.
Abstract: We investigate the consequence of failures, occurring on the electrical grid, on a telecommunication network We have focused on the Italian electrical transmission network and the backbone of the internet network for research (GARR) Electrical network has been simulated using the DC power flow method; data traffic on GARR by a model of the TCP/IP basic features The status of GARR nodes has been related to the power level of the (geographically) neighbouring electrical nodes (if the power level of a node is lower than a threshold, all communication nodes depending on it are switched off) The electrical network has been perturbed by lines removal: the consequent re-dispatching reduces the power level in all nodes This reduces the number of active GARR nodes and, thus, its Quality of Service (QoS) Averaging over many configurations of perturbed electrical network, we have correlated the degradation of the electrical network with that of the communication network Results point to a sizeable amplification of the effects of faults on the electrical network on the communication network, also in the case of a moderate coupling between the two networks

471 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202396
2022281
2021428
2020696
2019850
2018930