On Factors Affecting the Usage and Adoption of a Nation-wide TV Streaming Service

Using nine months of access logs comprising 1.9 Billion sessions to BBC iPlayer, we survey the UK ISP ecosystem to understand the factors affecting adoption and usage of a high bandwidth TV streaming application across different providers. We find evidence that connection speeds are important and that external events can have a huge impact for live TV usage. Then, through a temporal analysis of the access logs, we demonstrate that data usage caps imposed by mobile ISPs significantly affect usage patterns, and look for solutions. We show that product bundle discounts with a related fixed-line ISP, a strategy already employed by some mobile providers, can better support user needs and capture a bigger share of accesses. We observe that users regularly split their sessions between mobile and fixed-line connections, suggesting a straightforward strategy for offloading by speculatively pre-fetching content from a fixed-line ISP before access on mobile devices.Comment: In Proceedings of IEEE INFOCOM 201

Characterizing and Improving the Reliability of Broadband Internet Access

In this paper, we empirically demonstrate the growing importance of reliability by measuring its effect on user behavior. We present an approach for broadband reliability characterization using data collected by many emerging national initiatives to study broadband and apply it to the data gathered by the Federal Communications Commission's Measuring Broadband America project. Motivated by our findings, we present the design, implementation, and evaluation of a practical approach for improving the reliability of broadband Internet access with multihoming.Comment: 15 pages, 14 figures, 6 table

GRB070125: The First Long-Duration Gamma-Ray Burst in a Halo Environment

We present the discovery and high signal-to-noise spectroscopic observations of the optical afterglow of the long-duration gamma-ray burst GRB070125. Unlike all previously observed long-duration afterglows in the redshift range 0.5 < z 1.0 A) absorption features in the wavelength range 4000 - 10000 A. The sole significant feature is a weak doublet we identify as Mg II 2796 (W = 0.18 +/- 0.02 A), 2803 (W = 0.08 +/- 0.01) at z = 1.5477 +/- 0.0001. The low observed Mg II and inferred H I column densities are typically observed in galactic halos, far away from the bulk of massive star formation. Deep ground-based imaging reveals no host directly underneath the afterglow to a limit of R > 25.4 mag. Either of the two nearest blue galaxies could host GRB070125; the large offset (d >= 27 kpc) would naturally explain the low column density. To remain consistent with the large local (i.e. parsec scale) circum-burst density inferred from broadband afterglow observations, we speculate GRB070125 may have occurred far away from the disk of its host in a compact star-forming cluster. Such distant stellar clusters, typically formed by dynamical galaxy interactions, have been observed in the nearby universe, and should be more prevalent at z>1 where galaxy mergers occur more frequently.Comment: 8 pages, accepted in Ap

International Broadband Deployment: The Impact of Unbundling

This paper shows that unbundling an incumbent's infrastructure only results in a substantial improvement in broadband deployment for middle-income countries, but not for their high income counterparts. Our statistical analysis of approximately 100 countries showed that GDP per capita, population, competition and unbundling are all factors that can lead a carrier to provide broadband services in a country. The logit models show that unbundling has a significant positive impact on the availability of broadband services. The OLS analysis indicates that GDP per capita, population size, price, competition, the percentage of dial-up Internet users, and hosts all have positive effects on the number of subscribers. One implication of these results is that if a policy is to be implemented to promote broadband, it should either foster competition through unbundling and/or reduced prices. Efforts to develop local content can also improve broadband adoption.broadband; unbundling; competition

A Multi-perspective Analysis of Carrier-Grade NAT Deployment

As ISPs face IPv4 address scarcity they increasingly turn to network address translation (NAT) to accommodate the address needs of their customers. Recently, ISPs have moved beyond employing NATs only directly at individual customers and instead begun deploying Carrier-Grade NATs (CGNs) to apply address translation to many independent and disparate endpoints spanning physical locations, a phenomenon that so far has received little in the way of empirical assessment. In this work we present a broad and systematic study of the deployment and behavior of these middleboxes. We develop a methodology to detect the existence of hosts behind CGNs by extracting non-routable IP addresses from peer lists we obtain by crawling the BitTorrent DHT. We complement this approach with improvements to our Netalyzr troubleshooting service, enabling us to determine a range of indicators of CGN presence as well as detailed insights into key properties of CGNs. Combining the two data sources we illustrate the scope of CGN deployment on today's Internet, and report on characteristics of commonly deployed CGNs and their effect on end users

The Effect of Content on Global Internet Adoption and the Global “Digital Divide”

A country’s human capital and economic productivity increasingly depend on the Internet due to its expanding role in providing information and communications. This has prompted a search for ways to increase Internet adoption and narrow its disparity across countries – the global “digital divide.” Previous work has focused on demographic, economic, and infrastructure determinants of Internet access difficult to change in the short run. Internet content increases adoption and can be changed more quickly; however, the magnitude of its impact and therefore its effectiveness as a policy and strategy tool is previously unknown. Quantifying content’s role is challenging because of feedback (network effects) between content and adoption: more content stimulates adoption which in turn increases the incentive to create content. We develop a methodology to overcome this endogeneity problem. We find a statistically and economically significant effect, implying that policies promoting content creation can substantially increase adoption. Because it is ubiquitous, Internet content is also useful to affect social change across countries. Content has a greater effect on adoption in countries with more disparate languages, making it a useful tool to overcome linguistic isolation. Our results offer guidance for policy makers on country characteristics that influence adoption’s responsiveness to content and for Internet firms on where to expand internationally and how to quantify content investments.Internet, technology adoption, economic development, two-sided markets, network effects, technology diffusion, language, content

From BGP to RTT and Beyond: Matching BGP Routing Changes and Network Delay Variations with an Eye on Traceroute Paths

Many organizations have the mission of assessing the quality of broadband access services offered by Internet Service Providers (ISPs). They deploy network probes that periodically perform network measures towards selected Internet services. By analyzing the data collected by the probes it is often possible to gain a reasonable estimate of the bandwidth made available by the ISP. However, it is much more difficult to use such data to explain who is responsible of the fluctuations of other network qualities. This is especially true for latency, that is fundamental for several nowadays network services. On the other hand, there are many publicly accessible BGP routers that collect the history of routing changes and that are good candidates to be used for understanding if latency fluctuations depend on interdomain routing. In this paper we provide a methodology that, given a probe that is located inside the network of an ISP and that executes latency measures and given a set of publicly accessible BGP routers located inside the same ISP, decides which routers are best candidates (if any) for studying the relationship between variations of network performance recorded by the probe and interdomain routing changes. We validate the methodology with experimental studies based on data gathered by the RIPE NCC, an organization that is well-known to be independent and that publishes both BGP data within the Routing Information Service (RIS) and probe measurement data within the Atlas project