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Rethinking Virtual Network Embedding: Substrate Support for Path Splitting and Migration
"... Network virtualization is a powerful way to run multiple architectures or experiments simultaneously on a shared infrastructure. However, making efficient use of the underlying resources requires effective techniques for virtual network embedding—mapping each virtual network to specific nodes and li ..."
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Cited by 110 (0 self)
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Network virtualization is a powerful way to run multiple architectures or experiments simultaneously on a shared infrastructure. However, making efficient use of the underlying resources requires effective techniques for virtual network embedding—mapping each virtual network to specific nodes and links in the substrate network. Since the general embedding problem is computationally intractable, past research restricted the problem space to allow efficient solutions, or focused on designing heuristic algorithms. In this paper, we advocate a different approach: rethinking the design of the substrate network to enable simpler embedding algorithms and more efficient use of resources, without restricting the problem space. In particular, we simplify virtual link embedding by: i) allowing the substrate network to split a virtual link over multiple substrate paths and ii) employing path migration to periodically re-optimize the utilization of the substrate network. We also explore node-mapping algorithms that are customized to common classes of virtualnetwork topologies. Our simulation experiments show that path splitting, path migration, and customized embedding algorithms enable a substrate network to satisfy a much larger mix of virtual networks.
Virtual Routers on the Move: Live Router Migration as a Network-Management Primitive
"... The complexity of network management is widely recognized as one of the biggest challenges facing the Internet today. Point solutions for individual problems further increase system complexity while not addressing the underlying causes. In this paper, we argue that many network-management problems s ..."
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Cited by 87 (9 self)
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The complexity of network management is widely recognized as one of the biggest challenges facing the Internet today. Point solutions for individual problems further increase system complexity while not addressing the underlying causes. In this paper, we argue that many network-management problems stem from the same root cause—the need to maintain consistency between the physical and logical configuration of the routers. Hence, we propose VROOM (Virtual ROuters On the Move), a new network-management primitive that avoids unnecessary changes to the logical topology by allowing (virtual) routers to freely move from one physical node to another. In addition to simplifying existing network-management tasks like planned maintenance and service deployment, VROOM can also help tackle emerging challenges such as reducing energy consumption. We present the design, implementation, and evaluation of novel migration techniques for virtual routers with either hardware or software data planes. Our evaluation shows that VROOM is transparent to routing protocols and results in no performance impact on the data traffic when a hardware-based data plane is used.
A virtual network mapping algorithm based on subgraph isomorphism detection
- In Proc. of the first ACM SIGCOMM Workshop on Virtualized Infrastructure Systems and Architectures (VISA
, 2009
"... 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 ..."
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Cited by 61 (1 self)
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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.
DaVinci: Dynamically Adaptive Virtual Networks for a Customized Internet
- in Proc. CoNEXT
, 2008
"... Running multiple virtual networks, customized for different performance objectives, is a promising way to support diverse applications over a shared substrate. Despite being simple, a static division of resources between virtual networks can be highly inefficient, while dynamic resource allocation r ..."
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Cited by 32 (2 self)
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Running multiple virtual networks, customized for different performance objectives, is a promising way to support diverse applications over a shared substrate. Despite being simple, a static division of resources between virtual networks can be highly inefficient, while dynamic resource allocation runs the risk of instability. This paper uses optimization theory to show that adaptive resource allocation can be stable and can maximize the aggregate performance across the virtual networks. In the DaVinci architecture, each substrate link periodically reassigns bandwidth shares between its virtual links; while at a smaller timescale, each virtual network runs a distributed protocol that maximizes its own performance objective independently. Numerical experiments with a mix of delay-sensitive and throughputsensitive traffic show that the bandwidth shares converge quickly to the optimal values. We demonstrate that running several custom protocols in parallel and allocating resource adaptively can be more efficient, more flexible, and easier to manage than a compromise “one-size-fits-all ” design. 1.
Shadow configuration as a network management primitive
- In SIGCOMM
, 2008
"... Configurations for today’s IP networks are becoming increasingly complex. As a result, configuration management is becoming a major cost factor for network providers and configuration errors are becoming a major cause of network disruptions. In this paper, we present and evaluate the novel idea of s ..."
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Cited by 29 (0 self)
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Configurations for today’s IP networks are becoming increasingly complex. As a result, configuration management is becoming a major cost factor for network providers and configuration errors are becoming a major cause of network disruptions. In this paper, we present and evaluate the novel idea of shadow configurations. Shadow configurations allow configuration evaluation before deployment and thus can reduce potential network disruptions. We demonstrate using real implementation that shadow configurations can be implemented with low overhead.
Cabernet: Connectivity Architecture for Better Network Services ABSTRACT
"... Deploying and managing wide-area network services is exceptionally challenging. Despite having servers at many locations, a service provider must rely on an underlying besteffort network; a network provider can offer services over its own customized network, but only within limited footprint. In thi ..."
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Cited by 29 (0 self)
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Deploying and managing wide-area network services is exceptionally challenging. Despite having servers at many locations, a service provider must rely on an underlying besteffort network; a network provider can offer services over its own customized network, but only within limited footprint. In this paper, we propose Cabernet (Connectivity Architecture for Better Network Services), a three-layer network architecture that lowers the barrier for deploying wide-area services. We introduce the connectivity layer, which uses virtual links purchased from infrastructure providers to run virtual networks with the necessary geographic footprint, reliability, and performance for the service providers. As an example, we present a cost-effective way to support IPTV delivery through wide-area IP multicast that runs on top of a reliable virtual network. 1.
Network virtualization architecture: Proposal and initial prototype
- In Proceedings of ACM SIGCOMM VISA
, 2009
"... The tussle between reliability and functionality of the Internet is firmly biased on the side of reliability. New enabling technologies fail to achieve traction across the majority of ISPs. We believe that the greatest challenge is not in finding solutions and improvements to the Internet’s many pro ..."
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Cited by 29 (16 self)
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The tussle between reliability and functionality of the Internet is firmly biased on the side of reliability. New enabling technologies fail to achieve traction across the majority of ISPs. We believe that the greatest challenge is not in finding solutions and improvements to the Internet’s many problems, but in how to actually deploy those solutions and re-balance the tussle between reliability and functionality. Network virtualization provides a promising approach to enable the co-existence of innovation and reliability. We describe a network virtualization architecture as a technology for enabling Internet innovation. This architecture is motivated from both business and technical perspectives and comprises four main players. In order to gain insight about its viability, we also evaluate some of its components based on experimental results from a prototype implementation.
On Wireless Social Community Networks
- In IEEE INFOCOM
, 2008
"... Abstract—Wireless social community networks are emerging as a new alternative to providing wireless data access in urban areas. By relying on users in the network deployment, a wireless community can rapidly deploy a high-quality data access infrastructure in an inexpensive way. But, the coverage of ..."
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Cited by 24 (2 self)
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Abstract—Wireless social community networks are emerging as a new alternative to providing wireless data access in urban areas. By relying on users in the network deployment, a wireless community can rapidly deploy a high-quality data access infrastructure in an inexpensive way. But, the coverage of such a network is limited by the set of access points deployed by the users. Currently, it is not clear if this paradigm can serve as a replacement of existing centralized networks operating in licensed bands (such as cellular networks) or if it should be considered as a complimentary service only, with limited coverage. This question currently concerns many wireless network operators. In this paper, we study the dynamics of wireless social community networks by using a simple analytical model. In this model, users choose their service provider based on the subscription fee and the offered coverage. We show how the evolution of social community networks depends on their initial coverage, the subscription fee, and the user preferences for coverage. We conclude that by using an efficient static or dynamic pricing strategy, the wireless social community can obtain a high coverage. Using a game-theoretic approach, we then study a case where the mobile users can choose between the services provided by a licensed band operator and those of a social community. We show that for specific distribution of user preferences, there exists a Nash equilibrium for this non-cooperative game. I.
Network Virtualization – a View from the Bottom
"... The interest in network virtualization has been growing steadily among the networking community in the last few years. Network virtualization opens up new possibilities for the evolution path to the Future Internet by enabling the deployment of different architectures and protocols over a shared phy ..."
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Cited by 23 (3 self)
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The interest in network virtualization has been growing steadily among the networking community in the last few years. Network virtualization opens up new possibilities for the evolution path to the Future Internet by enabling the deployment of different architectures and protocols over a shared physical infrastructure. The deployment of network virtualization imposes new requirements and raises new issues in relation to how networks are provisioned, managed and controlled today. The starting point for this paper is the network virtualization reference model conceived in the framework of the EU funded 4WARD project. In this paper we look at network virtualization mainly from the perspective of the network infrastructure provider, following the 4WARD network virtualization architecture and evaluate the main issues and challenges to be faced in commercial operator environments.
Understanding Network Delay Changes Caused by Routing Events
- IN: PROC. OF ACM SIGMETRICS
, 2007
"... Network delays and delay variations are two of the most important network performance metrics directly impacting real-time applications such as voice over IP and time-critical financial transactions. This importance is illustrated by past work on understanding the delay constancy of Internet paths a ..."
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Cited by 22 (5 self)
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Network delays and delay variations are two of the most important network performance metrics directly impacting real-time applications such as voice over IP and time-critical financial transactions. This importance is illustrated by past work on understanding the delay constancy of Internet paths and recent work on predicting network delays using virtual coordinate systems. Merely understanding currently observed delays is insufficient, as network performance can degrade not only due to traffic variability but also as a result of routing changes. Unfortunately this latter effect so far has been ignored in understanding and predicting delay related performance metrics of Internet paths. Our work is the first to address this shortcoming by systematically analyzing changes in network delays and jitter of a diverse and comprehensive set of Internet paths. Using empirical measurements, we illustrate that routing changes can result in roundtrip delay increase of converged paths by more than 1 second. Surprisingly, intradomain routing changes can also cause such large delay increase. Given these observations, we develop a framework to analyze in detail the impact of routing changes on network delays between end-hosts. Using topology information and properties associated with routing changes, we explain the causes for observed delay fluctuations and more importantly identify routing changes that lead to predictable effects on delay-related metrics. Using our framework, we study the predictability of delay and jitter changes in response to both passively observed interdomain and actively measured intradomain routing changes.
