| 1. |
- Antichi, Gianni, et al.
(författare)
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ENDEAVOUR : A Scalable SDN Architecture For Real-World IXPs
- 2017
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Ingår i: IEEE Journal on Selected Areas in Communications. - : Institute of Electrical and Electronics Engineers (IEEE). - 0733-8716 .- 1558-0008. ; 35:11, s. 2553-2562
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Tidskriftsartikel (refereegranskat)abstract
- Innovation in interdomain routing has remained stagnant for over a decade. Recently, Internet eXchange Points (IXPs) have emerged as economically-advantageous interconnection points for reducing path latencies and exchanging ever increasing traffic volumes among, possibly, hundreds of networks. Given their far-reaching implications on interdomain routing, IXPs are the ideal place to foster network innovation and extend the benefits of software defined networking (SDN) to the interdomain level. In this paper, we present, evaluate, and demonstrate ENDEAVOUR, an SDN platform for IXPs. ENDEAVOUR can be deployed on a multi-hop IXP fabric, supports a large number of use cases, and is highly scalable, while avoiding broadcast storms. Our evaluation with real data from one of the largest IXPs, demonstrates the benefits and scalability of our solution: ENDEAVOUR requires around 70% fewer rules than alternative SDN solutions thanks to our rule partitioning mechanism. In addition, by providing an open source solution, we invite everyone from the community to experiment (and improve) our implementation as well as adapt it to new use cases.
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| 2. |
- Kathiravelu, Pradeeban, et al.
(författare)
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Moving Bits with a Fleet of Shared Virtual Routers
- 2018
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Ingår i: 2018 IFIP NETWORKING CONFERENCE (IFIP NETWORKING) AND WORKSHOPS. - : IEEE. ; , s. 352-360
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Konferensbidrag (refereegranskat)abstract
- The steady decline of IP transit prices in the past two decades has helped fuel the growth of traffic demands in the Internet ecosystem. Despite the declining unit pricing, bandwidth costs remain significant due to ever-increasing scale and reach of the Internet, combined with the price disparity between the Internet's core hubs versus remote regions. In the meantime, cloud providers have been auctioning underutilized computing resources in their marketplace as spot instances for a much lower price, compared to their on-demand instances. This state of affairs has led the networking community to devote extensive efforts to cloud-assisted networks - the idea of offloading network functionality to cloud platforms, ultimately leading to more flexible and highly composable network service chains. We initiate a critical discussion on the economic and technological aspects of leveraging cloud-assisted networks for Internet-scale interconnections and data transfers. Namely, we investigate the prospect of constructing a large-scale virtualized network provider that does not own any fixed or dedicated resources and runs atop several spot instances. We construct a cloud-assisted overlay as a virtual network provider, by leveraging third-party cloud spot instances. We identify three use case scenarios where such approach will not only be economically and technologically viable but also provide performance benefits compared to current commercial offerings of connectivity and transit providers.
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| 3. |
- Marcos, Pedro, et al.
(författare)
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A Survey on the Current Internet Interconnection Practices
- 2020
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Ingår i: Computer communication review. - : Association for Computing Machinery (ACM). - 0146-4833 .- 1943-5819. ; 50:1, s. 10-17
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Tidskriftsartikel (refereegranskat)abstract
- The Internet topology has significantly changed in the past years. Today, it is richly connected and flattened. Such a change has been driven mostly by the fast growth of peering infrastructures and the expansion of Content Delivery Networks as alternatives to reduce interconnection costs and improve traffic delivery performance. While the topology evolution is perceptible, it is unclear whether or not the interconnection process has evolved or if it continues to be an ad-hoc and lengthy process. To shed light on the current practices of the Internet interconnection ecosystem and how these could impact the Internet, we surveyed more than 100 network operators and peering coordinators. We divide our results into two parts: (i)(i) the current interconnection practices, including the steps of the process and the reasons to establish new interconnection agreements or to renegotiate existing ones, and the parameters discussed by network operators. In part (ii)(ii), we report the existing limitations and how the interconnection ecosystem can evolve in the future. We show that despite the changes in the topology, interconnecting continues to be a cumbersome process that usually takes days, weeks, or even months to complete, which is in stark contrast with the desire of most operators in reducing the interconnection setup time. We also identify that even being primary candidates to evolve the interconnection process, emerging on-demand connectivity companies are only fulfilling part of the existing gap between the current interconnection practices and the network operators' desires.
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| 4. |
- Marcos, Pedro, et al.
(författare)
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Dynam-IX : a Dynamic Interconnection eXchange
- 2018
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Ingår i: PROCEEDINGS OF THE 2018 APPLIED NETWORKING RESEARCH WORKSHOP (ANRW '18). - New York, NY, USA : Association for Computing Machinery (ACM). ; , s. 94-94
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Konferensbidrag (refereegranskat)
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| 5. |
- Marcos, Pedro, et al.
(författare)
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Dynam-IX : a Dynamic Interconnection eXchange
- 2018
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Ingår i: CONEXT'18. - New York, NY, USA : ASSOC COMPUTING MACHINERY. - 9781450360807 ; , s. 228-240
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Konferensbidrag (refereegranskat)abstract
- Autonomous Systems (ASes) can reach hundreds of networks via Internet eXchange Points (IXPs), allowing improvements in traffic delivery performance and competitiveness. Despite the benefits, any pair of ASes needs first to agree on exchanging traffic. By surveying 100+ network operators, we discovered that most interconnection agreements are established through ad-hoc and lengthy processes heavily influenced by personal relationships and brand image. As such, ASes prefer long-term agreements at the expense of a potential mismatch between actual delivery performance and current traffic dynamics. ASes also miss interconnection opportunities due to trust reasons. To improve wide-area traffic delivery performance, we propose Dynam-IX, a framework that allows operators to build trust cooperatively and implement traffic engineering policies to exploit the rich interconnection opportunities at IXPs quickly. Dynam-IX offers a protocol to automate the interconnection process, an intent abstraction to express interconnection policies, a legal framework to digitally handle contracts, and a distributed tamper-proof ledger to create trust among ASes. We build and evaluate a Dynam-IX prototype and show that an AS can establish tens of agreements per minute with negligible overhead for ASes and IXPs.
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| 6. |
- Alowayed, Y., et al.
(författare)
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Picking a partner : A fair blockchain based scoring protocol for autonomous systems
- 2018
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Ingår i: ANRW 2018 - Proceedings of the 2018 Applied Networking Research Workshop. - New York, NY, USA : Association for Computing Machinery (ACM). - 9781450355858 ; , s. 33-39
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Konferensbidrag (refereegranskat)abstract
- We tackle the problem of enabling Autonomous Systems to evaluate network providers on the basis of their adherence to Service Level Agreements (SLAs) regarding interconnection agreements. In current Internet practices, choices of interconnection partners are driven by factors such as word of mouth, personal relationships, brand recognition and market intelligence, and not by proofs of previous performance. Given that Internet eXchange Points provide increasingly more peering choices, rudimentary schemes for picking interconnection partners are not adequate anymore. Although the current interconnection ecosystem is shrouded in confidentiality, our key observation is that recently-emerged blockchain technology and advances in cryptography enable a privacy-preserving decentralized solution based on actual performance measurements. We propose the concept of SLA score to evaluate network providers and introduce a privacy-preserving protocol that allows networks to compute and verify SLA scores.
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| 7. |
- Anderson, Thomas, et al.
(författare)
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Assise: Performance and Availability via Client-local NVM in a Distributed File System
- 2020
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Konferensbidrag (refereegranskat)abstract
- The adoption of low latency persistent memory modules (PMMs) upends the long-established model of remote storage for distributed file systems. Instead, by colocating computation with PMM storage, we can provide applications with much higher IO performance, sub-second application failover, and strong consistency. To demonstrate this, we built the Assise distributed file system, based on a persistent, replicated coherence protocol that manages client-local PMM as a linearizable and crash-recoverable cache between applications and slower (and possibly remote) storage. Assise maximizes locality for all file IO by carrying out IO on process-local, socket-local, and client-local PMM whenever possible. Assise minimizes coherence overhead by maintaining consistency at IO operation granularity, rather than at fixed block sizes.We compare Assise to Ceph/BlueStore, NFS, and Octopus on a cluster with Intel Optane DC PMMs and SSDs for common cloud applications and benchmarks, such as LevelDB, Postfix, and FileBench. We find that Assise improves write latency up to 22x, throughput up to 56x, fail-over time up to 103x, and scales up to 6x better than its counterparts, while providing stronger consistency semantics.
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| 8. |
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| 9. |
- Canini, Marco, et al.
(författare)
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A NICE Way to Test OpenFlow Applications
- 2012
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Ingår i: Proceedings of the 9th USENIX Symposium on Networked Systems Design and Implementation (NSDI). - : Association for Computing Machinery (ACM).
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Konferensbidrag (refereegranskat)abstract
- The emergence of OpenFlow-capable switches enables exciting new network functionality, at the risk of programming errors that make communication less reliable. The centralized programming model, where a single controller program manages the network, seems to reduce the likelihood of bugs. However, the system is inherently distributed and asynchronous, with events happening at different switches and end hosts, and inevitable delays affecting communication with the controller. In this paper, we present efficient, systematic techniques for testing unmodified controller programs. Our NICE tool applies model checking to explore the state space of the entire system—the controller, the switches, and the hosts. Scalability is the main challenge, given the diversity of data packets, the large system state, and the many possible event orderings. To address this, we propose a novel way to augment model checking with symbolic execution of event handlers (to identify representative packets that exercise code paths on the controller). We also present a simplified OpenFlow switch model (to reduce the state space), and effective strategies for generating event interleavings likely to uncover bugs. Our prototype tests Python applications on the popular NOX platform. In testing three real applications—a MAC-learning switch, in-network server load balancing, and energy-efficient traffic engineering—we uncover eleven bugs.
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| 10. |
- Canini, Marco, et al.
(författare)
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Automating the Testing of OpenFlow Applications
- 2011
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Ingår i: Proceedings of the 1st International Workshop on Rigorous Protocol Engineering (WRiPE).
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Konferensbidrag (refereegranskat)abstract
- Software-defined networking, and the emergence of OpenFlow-capable switches, enables a wide range of new network functionality. However, enhanced programmability inevitably leads to more software faults (or bugs). We believe that tools for testing OpenFlow programs are critical to the success of the new technology. However, the way OpenFlow applications interact with the data plane raises several challenges. First, the space of possible inputs (e.g., packet headers and inter-packet timings) is huge. Second, the centralized controller has a indirect view of the traffic and experiences unavoidable delays in installing rules in the switches. Third, external factors like user behavior (e.g., mobility) and higher-layer protocols (e.g., the TCP state machine) affect the correctness of OpenFlow programs. In this work-in-progress paper, we extend techniques for symbolic execution to generate inputs that systematically explore the space of system executions. First, we analyze controller applications to identify equivalence classes of packets that exercise different parts of the code. Second, we propose several network models with increasing precision, ranging from simple traffic models to live testing on the target network. Initial experiences with our prototype, which symbolically executes OpenFlow applications written in Python, suggest that our techniques can help programmers identify bugs in their OpenFlow programs.
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