This is a summary report by the organizers of the 6th TMA PhD school held in Louvain-la-Neuve on 5-6 April 2016. The insight and feedback received about the event might turn useful for the organization of future editions and similar events targeting students and young researchers.
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.
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.
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.
We live in a world in which there is a great disparity between the lives of the rich and the poor. Technology offers great promise in bridging this gap. In particular, wireless technology unfetters developing communities from the constraints of infrastructure providing a great opportunity to leapfrog years of neglect and technological waywardness. In this paper, we highlight the role of resource pooling for wireless networks in the developing world. Resource pooling involves (i) abstracting a collection of networked resources to behave like a single unified resource pool and (ii) developing mechanisms for shifting load between the various parts of the unified resource pool. The popularity of resource pooling stems from its ability to provide resilience, high utilization, and flexibility at an acceptable cost. We show that “resource pooling”, which is very popular in its various manifestations, is the key unifying principle underlying a diverse number of successful wireless technologies (such as white space networking, community networks, etc.). We discuss various applications of resource pooled wireless technologies and provide a discussion on open issues.
On 10-12 February 2016, CAIDA hosted the eighth Workshop on Active Internet Measurements (AIMS-8) as part of our series of Internet Statistics and Metrics Analysis (ISMA) workshops. This workshop series provides a forum for stakeholders in Internet active measurement projects to communicate their interests and concerns, and explore cooperative approaches to maximizing the collective benefit of deployed infrastructure and gathered measurements. Discussion topics included: infrastructure development status and plans; experimental design, execution, and cross-validation; challenges to incentivize hosting, sharing, and using measurement infrastructure; data access, sharing, and analytics; and challenges of emerging high bandwidth network measurement infrastructure. Other recurrent topics included paths toward increased interoperability and cooperative use of infrastructures, and ethical frameworks to support active Internet measurement. Materials related to the workshop are at
http://www.caida.org/workshops/aims/1602/.
Control planes for global carrier networks should be programmable and scalable. Neither traditional control planes nor new SDN-based control planes meet both of these goals. Here we propose a framework for recursive routing computations that combines the best of SDN (programmability through centralized controllers) and traditional networks (scalability through hierarchy) to achieve these two desired properties. Through simulation on graphs of up to 10,000 nodes, we evaluate our design’s ability to support a variety of unicast routing and traffic engineering solutions, while incorporating a fast failure recovery mechanism based on network virtualization.
While software-defined networks have received significant attention in recent years, the networks studied often lack multiple orders of magnitude from today’s global carrier networks in terms of geographical span and nodal scale. Hence, this paper sets forth a recursive routing computation framework that balances the programmability of SDNs with the scalability of a traditional hierarchical structure. Simulations of about 10,000 nodes are used to show the viability of such an approach. Remarkably, the authors show that their recovery approach can offer “five 9s” of network repair even under a heavy link failure scenario.
Technical papers
Editorials
Technical papers
Editorials