Overlay Routing Research Articles

A novel hybrid immune-based GA for dynamic routing to multiple destinations for overlay networks

Overlay networks play an important role in group communication applications in Internet. These applications require better efficiency in terms of delay, cost and load balancing. This paper presents an artificial immune system (AIS)-based hybrid genetic algorithm for the construction of Quality of Service (QoS) multicast tree among multicast service nodes in overlay network which optimizes path delivery, load-balancing variance and cost under bounded delay–degree constraint. This paper proposes an alternative AIS-based approach to handle the constraints instead of penalty function in overlay multicast routing problem. The clonal selection method of AIS is incorporated into the genetic algorithm (GA) to improve the diversity–convergence relationship which leads to optimized results. Proposed algorithm has the following features: (1) embedded problem specific local search function along with random point crossover to fine tune the search; (2) AIS principle is used to solve the constraints in GA; (3) clonal selection method to get the optimized results. Adaptable procedure is embedded into algorithm to handle the end user join/end user drop. Non-parametric statistical analysis has performed to show the significant difference among the proposed and existing algorithms. Simulation results reveal that our proposed algorithm produces better results in terms of cost, average path length, user rejection rate and convergence. Statistical analysis is also performed to assure the significance of the differences among the tested algorithms.

Resolving Cross-Layer Conflict Between Overlay Routing and Traffic Engineering

Overlay routing is known to cause undesired instability in a network by operating in a selfish manner. The objectives of overlay routing, such as optimizing end-to-end latency, are often in conflict with the objectives of traffic engineering (TE) in the native layer, which is concerned about balancing load. In our paper, we build on past research that has investigated the recurring noncooperative interaction between overlay routing and traffic engineering, and develop strategies that improve the routing performance of a particular layer with incomplete information about the other layer. In our strategies, one layer acts as a <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">leader</i> that predicts the <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">follower</i> 's reaction and undertakes countermeasures to prevent future deterioration in performance. Specifically, we propose two classes of strategies- <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">friendly</i> or <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">hostile</i> -for each layer. By simulating under different network characteristics, we show that these preemptive strategies achieve near-optimal performance for the leader and increase the overall stability of the network. Furthermore, we observe that the best performance for a particular layer is achieved only when the goals of the other layer are completely violated, thereby motivating a higher level of selfishness.

Research on Internet Overlay Routing

对互联网覆盖路由相关研究工作进行了调研;按照Internet分层概念重点考查了网络层和传输层的覆盖路由的结构和方法;并且考查了覆盖路由其他相关问题的研究,包括覆盖路由性能的影响因素、多个覆盖网络路由之间的相互作用等.分析了已有研究工作的关键技术的优缺点.最后讨论了未来可能的研究方向,为互联网覆盖路由的研究提供参考.;This paper surveys related research work of Internet overlay routing, and focuses on the structure and methods of Internet overlay routing on network layer and transport layer according to Internet layering scheme. Apart from that, other related aspects of overlay routing are discussed, including the impacts on overlay routing performance, and interactions between multiple overlay networks routing, etc. The advantages and disadvantages in the key technologies of related research work are analyzed. At last, the possible future research directions are discussed as references for the research of Internet overlay routing.

A Measurement Study on the Benefits of Open Routers for Overlay Routing

As the rapid proliferation of multimedia communications has been significantly challenging the Internet on providing a high-quality transporting service to achieve desirable audio and video user experience, overlay routing is proposed as a practical technique to complement some inherent deficiencies of the current IP routing service. While many research and realistic systems have proven the effectiveness of overlay routing on improving end-to-end (E2E) performance, this paper performs a measurement study on the potential benefits of open router s, a novel promising technical concept emerging recently, to boost overlay routing for multimedia communications. Based on analysis of a large amount of measurements collected between more than 200 PlanetLab sites over the world, our results show that when being deployed appropriately, even a small number of open routers will be able to remarkably enhance overlay routing’s ability of improving E2E performance for multimedia communications. Accordingly, several practical heuristics for selecting suitable places to deploy open routers are proposed and comparatively evaluated based on real Internet topological and routing data.

Overlay multicast routing algorithm with minimum overlay cost

Compared with IP multicast, overlay multicast usually consumes more underlying network resources. Therefore, utilizing the underlying network resources effectively has some practical significance when constructing the multicast delivery tree based on overlay network. The concept of overlay cost was proposed, and the overlay multicast routing problem was defined to find a degree and delay constrained spanning tree with the minimum overlay cost for an undirected complete graph. The goal of the solution was to satisfy the applications' requirements and the end hosts' performance needs, and to make the consumption of underlying network resources minimum at the same time. A heuristic genetic algorithm for this problem was given, and the simulation results verify the effectiveness of the algorithm.

On the Placement of Infrastructure Overlay Nodes

Overlay routing has emerged as a promising approach to improving performance and reliability of Internet paths. To fully realize the potential of overlay routing under the constraints of deployment costs in terms of hardware, network connectivity and human effort, it is critical to carefully place infrastructure overlay nodes to balance the tradeoff between performance and resource constraints. In this paper, we investigate approaches to perform intelligent placement of overlay nodes to facilitate (i) resilient routing and (ii) TCP performance improvement. We formulate objective functions to capture application behavior: reliability and TCP performance, and develop several placement algorithms, which offer a wide range of tradeoffs in complexity and required knowledge of the client-server location and traffic load. Using simulations on synthetic and real Internet topologies, and PlanetLab experiments, we demonstrate the effectiveness of the placement algorithms and objective functions developed, respectively. We conclude that a hybrid approach combining greedy and random approaches provides the best tradeoff between computational efficiency and accuracy. We also uncover the fundamental challenge in simultaneously optimizing for reliability and TCP performance, and propose a simple unified algorithm to achieve both.

Towards the Future Internet: virtual networks for convergent services

In this paper we will investigate the deficiencies and the achievements of today's Internet. We outline how Network Virtualization (NV) can overcome the shortfalls of today's networks, how it paves the way for the Future Internet, and how it can facilitate the convergence of currently different networks. The major building blocks of NV are the a) use of application-specific routing overlays, b) the safe consolidation of resources by OS virtualization on a generic infrastructure, and c) the exploitation of the network diversity for performance enhancements and for new business models, such as the provisioning of intermediates nodes or path oracles. Furthermore, we detail a more elaborate concept for network virtualization, which is denoted as Transport Virtualization (TV). TV transfers the concept of location independence of resources to the area of data transport in communication networks.

CORS: A cooperative overlay routing service to enhance interactive multimedia communications

As interactive multimedia communications are developing rapidly on the Internet, they present stringent challenges on end-to-end (E2E) performance. On the other hand, however, the Internet’s architecture (IPv4) remains almost the same as it was originally designed for only data transmission purpose, and has experienced big hurdle to actualize QoS universally. This paper designs a cooperatively overlay routing service (CORS) aiming to overcome the performance limit inherent in the Internet’s IP-layer routing service. The key idea of CORS is to efficiently compose a number of eligible application-layer paths with suitable relays in the overlay network. Besides the direct IP path, CORS can transfer data simultaneously through one or more application-layer paths to adaptively satisfy the data’s application-specific requirements on E2E performance. Simulation results indicate the proposed schemes are scalable and effective. Practical experiments based on a prototype implemented on PlanetLab show that CORS is feasible to enhance the transmission reliability and the quality of multimedia communications.

Improving peer connectivity in wide-area overlays of virtual workstations

Self-configuring virtual networks rely on structured P2P routing to provide seamless connectivity among nodes through overlay routing of virtual IP packets, support decentralized hole-punching to establish bi-directional communication links among nodes behind network address translators, and dynamic configuration of virtual IP addresses. Our experiences with deployments of virtual networks in support of wide-area overlays of virtual workstations (WOWs) reveal that connectivity constraints imposed by symmetric NATs and by Internet route outages often hinder P2P overlay structure maintenance and routability, subsequently limiting the ability of WOWs to deliver high-throughput computing through aggregation of resources in different domains.In this paper, we describe and evaluate two novel approaches which are generally applicable and fully decentralized, and show that they improve routability of structured P2P networks in such connectivity constrained environments: (1) a fault-tolerant routing algorithm based on simulated annealing from optimization theory, and (2) tunneling of connections between adjacent nodes (in the P2P identifier space) over common neighbors when direct communication is not possible. Simulation-based analyses show that (1) when pairs of nodes only have 70% chance of being able to communicate directly, the described approaches improve all-to-all routability of the network from 90% to 99%, and (2) even when only 70% of the nodes are behind NATs that include symmetric NATs, these techniques improve the all-to-all connectivity of the network from less than 95% to more than 99%. We have implemented these techniques in the IP-over-P2P (IPOP) virtual network and have conducted experiments with a 180-node WOW Condor pool, demonstrating that, at 81% probability of establishing a pair-wise connection, annealing and tunneling combined allow all nodes to be connected to the pool, compared to only 160 nodes in the absence of these techniques.

Evaluation of Free-Riding Traffic Problem in Overlay Routing and Its Mitigation Method

Recent research on overlay networks has revealed that user-perceived network performance could be improved by an overlay routing mechanism. The effectiveness of overlay routing is mainly a result of the policy mismatch between the overlay routing and the underlay IP routing operated by ISPs. However, this policy mismatch causes a “free-riding” traffic problem, which may become harmful to the cost structure of Internet Service Providers. In the present paper, we define the free-riding problem in the overlay routing and evaluate the degree of free-riding traffic to reveal the effect of the problem on ISPs. We introduce a numerical metric to evaluate the degree of the free-riding problem and confirm that most multihop overlay paths that have better performance than the direct path brings the free-riding problem. We also discuss the guidelines for selecting paths that are more effective than the direct path and that mitigate the free-riding problem.

Effectiveness of Overlay Routing Based on Delay and Bandwidth Information

Recent research on overlay networks has revealed that user-perceived network performance, such as end-to-end delay performance, could be improved by an overlay routing mechanism. However, these studies consider only end-to-end delay, and few studies have focused on bandwidth-related information, such as available bandwidth and TCP throughput, which are important performance metrics especially for long-lived data transmission. In the present paper, we investigate the effect of overlay routing both delay and bandwidth-related information, based on the measurement results of network paths between PlanetLab nodes. We consider three metrics for selecting the overlay route: end-to-end delay, available bandwidth, and TCP throughput. We then show that the available bandwidth-based overlay routing provides significant gain, as compared with delay-based routing. We further reveal the correlation between the latency and available bandwidth of the overlay paths and propose several guidelines for selecting an overlay path.

Inter-domain policy violations in multi-hop overlay routes: Analysis and mitigation

The Internet is a complex structure arising from the interconnection of numerous autonomous systems (AS), each exercising its own administrative policies to reflect the commercial agreements behind the interconnection. However, routing in service overlay networks is quite capable of violating these policies to its advantage. To prevent these violations, we see an impending drive in the current Internet to detect and filter overlay traffic. In this paper, we first present results from a case study overlay network, constructed on top of PlanetLab, that helps us gain insights into the frequency and characteristics of the different inter-domain policy violations. Further, we investigate the impact of two types of overlay traffic filtering that aim to prevent these routing policy violations: blind filtering and policy-aware filtering. We show that such filtering can be detrimental to the performance of overlay routing. We next consider two approaches that allow the overlay network to realize the full advantage of overlay routing in this context. In the first approach, overlay nodes are added so that good overlay paths do not represent inter-domain policy violations. In the second approach, the overlay acquires permits from certain ASes that allow certain policy violations to occur. We develop a single cost-sharing framework that allows the incorporation of both approaches into a single strategy. We formulate and solve an optimization problem that aims to determine how the overlay network should allocate a given budget between paying for additional overlay nodes and paying for permits (transit and exit) to ASes. We illustrate the use of this approach on our case study overlay network and evaluate its performance under varying network characteristics.

UFO

Conventional wisdom has held that routing protocols cannot achieve both scalability and high availability. Despite scaling relatively well, today's Internet routing system does not react quickly to changing network conditions (e.g., link failures or excessive congestion). Overlay networks, on the other hand, can respond quickly to changing network conditions, but their reliance on aggressive probing does not scale to large topologies. The paper presents a layered routing architecture called UFO (Underlay Fused with Overlays), which achieves the best of both worlds by having the "underlay" provide explicit notification about network conditions to help improve the efficiency and scalability of routing overlays.

Shortest-path routing in randomized DHT-based Peer-to-Peer systems

Randomized DHT-based Peer-to-Peer (P2P) systems grant nodes certain flexibility in selecting their overlay neighbors, leading to irregular overlay structures but to better overall performance in terms of path latency, static resilience and local convergence. However, routing in the presence of overlay irregularity is challenging. In this paper, we propose a novel routing protocol, RASTER, that approximates shortest overlay routes between nodes in randomized DHTs. Unlike previously proposed routing protocols, RASTER encodes and aggregates routing information. Its simple bitmap-encoding scheme together with the proposed RASTER routing algorithm enable a performance edge over current overlay routing protocols. RASTER provides a forwarding overhead of merely a small constant number of bitwise operations, a routing performance close to optimal, and a better resilience to churn. RASTER also provides nodes with the flexibility to adjust the size of the maintained routing information based on their storage/processing capabilities. The cost of storing and exchanging encoded routing information is manageable and grows logarithmically with the number of nodes in the system.

New algebraic design for better P2P Features (abstract only)

Lately P2P application routing got interest and finding better routing and increasing performance and security is real challenge these days. Mostly research use overlay routing even using interconnection network design dynamically. Goal is to route a message to a destination whose IP address is not known which eliminates the need for large routing tables. Nevertheless, the overlay network could become wasteful because outgoing traffic may take a route longer than necessary. In this abstract, we propose a new design for P2P features. These new design is to combine physical and logical networks to reduce traffic and improving performance and security. This new design provides node organization for faster searching. Work used simulation program to show these new design better performance than existing design. Algorithm of new routing is defined mathematical algebraic model to show every case. Our next step is to actually improving localizing design with new overlay network design.

Enhancing end-to-end availability and performance via topology-aware overlay networks

This paper proposes a novel overlay architecture to improve availability and performance of end-to-end communication over the Internet. Connectivity and network availability are becoming business-critical resources as the Internet is increasingly utilized as a business necessity. For example, traditional voice and military systems are turning into IP-based network applications. With these applications, even short-lived failures of the Internet infrastructure can generate significant losses. To satisfy these needs, the concept of overlay networks has been widely discussed. However, in the previous studies of overlay networks, a measurable number of path outages were still unavoidable even with use of such overlay networks. We believe that an overlay network's ability to quickly recover from path outages and congestion is limited unless we ensure path independence at the IP layer. Hence, we develop a simple but effective overlay architecture increasing path independence without degrading performance. The proposed overlay architecture enhances prior studies in the following ways: (1) we deploy overlay nodes considering topology and latency information inside an ISP and also across ISP boundaries; (2) we use a source-based single-hop overlay routing combined with the above topology-aware node deployment; (3) we increase the usage of multi-homing environment at endhosts. In this framework, we develop measurement-based heuristics using extensive data collection from 232 points in 10 ISPs, and 100 PlanetLab nodes. We also validate the proposed framework using real Internet outages to show that our architecture is able to provide a significant amount of resilience to real-world failures.

Stability of virtual network topology control for overlay routing services

Overlay networks achieve new functionality and enhance network performance by enabling control of routing at the application layer. However, this approach results in degradations of underlying networks due to the selfish behavior of overlay networks. We discuss the stability of virtual network topology (VNT) control under overlay networks that perform dynamic routing updates. We find that the dynamics of routing on overlay networks cause a high fluctuation in the traffic demand matrix, which leads to significant VNT control instability. To overcome this instability, we introduce three extensions, hysteresis, two-state utilization hysteresis, and filtering, to VNT control. Simulation results show that the hysteresis mechanism improves network stability, but cannot always improve network performance. We therefore extend the hysteresis mechanism and show that it improves both network stability and performance. However, this extension requires a lot of time for the VNT to converge to a stable state. To achieve fast convergence, we use a filtering method for VNT control. Through simulations, we prove that our methods achieve stability against overlay routing without loss of adaptability for changes in traffic demand.

Managing inter-domain traffic in the presence of bittorrent file-sharing

Overlay routing operating in a selfish manner is known to cause undesired instability when it interacts with native layer routing. We observe similar selfish behavior with the BitTorrent protocol, where its performance-awareness causes it to constantly alter the routing decisions (peer and piece selection). This causes fluctuations in the load experienced by the underlying native network. By using real BitTorrent traces and a comprehensive simulation with different network characteristics, we show that BitTorrent systems easily disrupt the load balance across inter-domain links. Further, we find that existing native layer traffic management schemes suffer from several downsides and are not conducive to deployment. To resolve this dilemma, we propose two BitTorrent strategies that are effective in resolving the cross-layer conflict.

Path selection using available bandwidth estimation in overlay-based video streaming

IP networks present a challenging environment for video streaming because they do not provide throughput, jitter, or loss rate guarantees. In this work, we focus on improving the perceived quality of video streaming through dynamic path selection. Selecting one of several Internet paths is possible using multihoming and/or an overlay routing infrastructure. We conduct an experimental comparison of various measurement-based path selection techniques for video streaming. The path selection is based on the measurement of network-layer metrics, such as loss rate, jitter or available bandwidth, while the video quality is evaluated based on the VQM tool. Our experiments show that the most effective technique for adaptive path selection relies on an estimate of the lower bound of the available bandwidth variation range. We show how to perform such measurements using the video packets, eliminating the measurement overhead in the selected path. Finally, we show that adaptive path selection is more effective than a simple, but commonly used, form of FEC.

Inconsistency of logical and physical topologies for overlay networks and its effect on file transfer delay

In overlay networks consisting of underlying physical nodes and links, data files are transferred by overlay routing managed at application level. The end-to-end file transfer delay depends on both logical and physical topologies resulting from overlay routing. In this paper, we focus on six types of four-terminal four-router physical networks, and investigate the impact of topology inconsistency on the file transfer delay. The analysis model is based on a two-layer queueing network, taking into account both logical and physical topologies. The model is validated in comparison with ns-2 simulation. Numerical examples show that the end-to-end file transfer delay is small when both logical and physical topologies are the same. It is also observed that the end-to-end delay significantly depends on the traffic intensity for some logical topologies, regardless of physical topology.