Tag Archives: scientific

A Techno-Economic Approach for Broadband Deployment in Underserved Areas

Ramakrishnan Durairajan, Paul Barford

A large body of economic research has shown the strong correlation between broadband connectivity and economic productivity. These findings motivate government agencies such as the FCC in the US to provide incentives to services providers to deploy broadband infrastructure in unserved or underserved areas. In this paper, we describe a framework for identifying target areas for network infrastructure deployment. Our approach considers (i) infrastructure availability, (ii) user demographics, and (iii) deployment costs. We use multi-objective optimization to identify geographic areas that have the highest concentrations of un/underserved users and that can be upgraded at the lowest cost. To demonstrate the efficacy of our framework, we consider physical infrastructure and demographic data from the US and two different deployment cost models. Our results identify a list of counties that would be attractive targets for broadband deployment from both cost and impact perspectives. We conclude with discussion on the implications and broader applications of our framework.
Download the full article DOI: 10.1145/3089262.3089265

Principles for Measurability in Protocol Design

Mark Allman, Robert Beverly, Brian Trammell

Measurement has become fundamental to the operation of networks and at-scale services—whether for management, security, diagnostics, optimization, or simply enhancing our collective understanding of the Internet as a complex system. Further, measurements are useful across points of view—from end hosts to enterprise networks and data centers to the wide area Internet. We observe that many measurements are decoupled from the protocols and applications they are designed to illuminate. Worse, current measurement practice often involves the exploitation of side-effects and unintended features of the network; or, in other words, the artful piling of hacks atop one another. This state of affairs is a direct result of the relative paucity of diagnostic and measurement capabilities built into today’s network stack.

Given our modern dependence on ubiquitous measurement, we propose measurability as an explicit low-level goal of current protocol design, and argue that measurements should be available to all network protocols throughout the stack. We seek to generalize the idea of measurement within protocols, e.g., the way in which TCP relies on measurement to drive its end-to-end behavior. Rhetorically, we pose the question: what if the stack had been built with measurability and diagnostic support in mind? We start from a set of principles for explicit measurability, and define primitives that, were they supported by the stack, would not only provide a solid foundation for protocol design going forward, but also reduce the cost and increase the accuracy of measuring the network.
Download the full article DOI: 10.1145/3089262.3089264

Exploring Domain Name Based Features on the Effectiveness of DNS Caching

Shuai Hao, Haining Wang.

DNS cache plays a critical role in domain name resolution, providing (1) high scalability at Root and Top-level-domain (TLD) name servers with reduced workloads and (2) low response latency to clients when the resource records of the queried domains are cached. However, the pervasive misuses of domain names, e.g., the domains of “one-time-use” pattern, have negative impact on the effectiveness of DNS caching as the cache has been filled with those entries that are highly unlikely to be retrieved. In this paper, we investigate such misuse and identify domain name-based features to characterize those one-time domains. By leveraging the features that are explicitly available from the domain name itself, we build a classifier to combine these features, propose simple policy modifications on caching resolvers for improving DNS cache performance, and validate their efficacy using real traces.

Download the full article DOI: 10.1145/3041027.3041032

On the Potential Abuse of IGMP

Matthew Sargent, John Kristoff, Vern Paxson, Mark Allman.

In this paper we investigate the vulnerability of the Internet Group Management Protocol (IGMP) to be leveraged for denial-of-service (DoS) attacks. IGMP is a connectionless protocol and therefore susceptible to attackers spoofing a third-party victim’s source address in an effort to coax responders to send their replies to the victim. We find 305K IGMP responders that will indeed answer queries from arbitrary Internet hosts. Further, the responses are often larger than the requests, hence amplifying the attacker’s own expenditure of bandwidth. We conclude that attackers can coordinate IGMP responders to mount sizeable DoS attacks.

Download the full article DOI: 10.1145/3041027.3041031

A Database Approach to SDN Control Plane Design

Bruce Davie, Teemu Koponen, Justin Pettit, Ben Pfaff, Martin Casado, Natasha Gude, Amar Padmanabhan, Tim Petty, Kenneth Duda, Anupam Chanda.

Software-defined networking (SDN) is a well-known example of a research idea that has been reduced to practice in numerous settings. Network virtualization has been successfully developed commercially using SDN techniques. This paper describes our experience in developing production-ready, multi-vendor implementations of a complex network virtualization system. Having struggled with a traditional network protocol approach (based on OpenFlow) to achieving interoperability among vendors, we adopted a new approach. We focused first on defining the control information content and then used a generic database protocol to synchronize state between the elements. Within less than nine months of starting the design, we had achieved basic interoperability between our network virtualization controller and the hardware switches of six vendors. This was a qualitative improvement on our decidedly mixed experience using OpenFlow. We found a number of benefits to the database approach, such as speed of implementation, greater hardware diversity, the ability to abstract away implementation details of the hardware, clarified state consistency model, and extensibility of the overall system.

Download the full article DOI: 10.1145/3041027.3041030

Towards a Context-Aware Forwarding Plane in Named Data Networking supporting QoS

Daniel Posch, Benjamin Rainer, Hermann Hellwagner.

The emergence of Information-Centric Networking (ICN) provides considerable opportunities for context-aware data distribution in the network’s forwarding plane. While packet forwarding in classical IP-based networks is basically predetermined by routing, ICN foresees an adaptive forwarding plane considering the requirements of network applications. As research in this area is still at an early stage, most of the work so far focused on providing the basic functionality, rather than on considering the available context information to improve Quality of Service (QoS). This article investigates to which extent existing forwarding strategies take account of the available context information and can therefore increase service quality. The article examines a typical scenario encompassing different user applications (Voice over IP, video streaming, and classical data transfer) with varying demands (context), and evaluates how well the applications’ requirements are met by the existing strategies.

Download the full article DOI: 10.1145/3041027.3041029

CliMB: Enabling Network Function Composition with Click Middleboxes

Rafael Laufer, Massimo Gallo, Diego Perino, Anandatirtha Nandugudi.

Click has significant advantages for middlebox development, including modularity, extensibility, and reprogrammability. Despite these features, Click still has no native TCP support and only uses nonblocking I/O, preventing its applicability to middleboxes that require access to application data and blocking I/O. In this paper, we attempt to bridge this gap by introducing Click middleboxes (CliMB). CliMB provides a full-fledged modular TCP layer supporting TCP options, congestion control, both blocking and nonblocking I/O, as well as socket and zero-copy APIs to applications. As a result, any TCP network function may now be realized in Click using a modular L2-L7 design. As proof of concept, we develop a zero-copy SOCKS proxy using CliMB that shows up to 4x gains compared to an equivalent implementation using the Linux in-kernel network stack.

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Latency Measurement as a Virtualized Network Function using Metherxis

Diego Rossi Mafioletti , Alextian Bartholomeu Liberatto , Rodolfo da Silva Villaça, Cristina Klippel Dominicini, Magnos Martinello, Moises Renato Nunes Ribeiro.

Network latency is critical to the success of many highspeed, low-latency applications. RFC 2544 discusses and defines a set of tests that can be used to describe the performance characteristics of a network device. However, most of the available measurement tools cannot perform all the tests as described in this standard. As a novel approach, this paper proposes Metherxis, a system that can be implemented on general purpose hardware and enables Virtualized Network Functions (VNFs) to measure network device latency with micro-second grade accuracy. Results show that Metherxis achieves highly accurate latency measurements when compared to OFLOPS, a well known measurement tool.

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Measuring the Quality of Experience of Web users

Enrico Bocchi, Luca De Cicco , Dario Rossi.

Measuring quality of Web users experience (WebQoE) faces the following trade-off. On the one hand, current practice is to resort to metrics, such as the document completion time (onLoad), that are simple to measure though knowingly inaccurate. On the other hand, there are metrics, like Google’s SpeedIndex, that are better correlated with the actual user experience, but are quite complex to evaluate and, as such, relegated to lab experiments. In this paper, we first provide a comprehensive state of the art on the metrics and tools available for WebQoE assessment. We then apply these metrics to a representative dataset (the Alexa top-100 webpages) to better illustrate their similarities, differences, advantages, and limitations. We next introduce novel metrics, inspired by Google’s SpeedIndex, that offer significant advantage in terms of computational complexity, while maintaining a high correlation with the SpeedIndex. These properties make our proposed metrics highly relevant and of practical use.

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