As the distribution of the video over the Internet becomes main- stream and its consumption moves from the computer to the TV screen, user expectation for high quality is constantly increasing. In this context, it is crucial for content providers to understand if and how video quality affects user engagement and how to best invest their resources to optimize video quality. This paper is a first step towards addressing these questions. We use a unique dataset that spans different content types, including short video on demand (VoD), long VoD, and live content from popular video con- tent providers. Using client-side instrumentation, we measure quality metrics such as the join time, buffering ratio, average bitrate, rendering quality, and rate of buffering events.

Data centers deploy a variety of middleboxes (e.g., firewalls, load balancers and SSL offloaders) to protect, manage and improve the performance of applications and services they run. Since existing networks provide limited support for middleboxes, administrators typically overload path selection mechanisms to coerce traffic through the desired sequences of middleboxes placed on the network path. These ad-hoc practices result in a data center network that is hard to configure and maintain, wastes middlebox resources, and cannot guarantee middlebox traversal under network churn.

We propose an economic model based on user utility to study the adoption of new network architectures such as IPv6. We use mathematical analysis and simulation studies to understand the role of various factors such as user and network benefits, switching costs, and the impact of converters on the adoption of new network architectures. In addition to corroborating various commonly held beliefs about new network architecture adoption, our analysis and simulation studies also reveal several surprising and non-intuitive results. For example, while in general, increasing the efficiency of converters hastens the adoption of new network architectures, there are cases in which more efficient converters hinder the adoption of such architectures. This and other results in the paper increase our understanding of new network architecture adoption and guide the design and implementation of mechanisms to hasten new network architecture adoption.

The rapid emergence of Wi-Fi hotspots (access points), that are aimed at providing broadband wireless access to users in and around places of commercial interest, presents the unique problem of integrating existing cellular networks with these. We present a novel architecture that explores the interoperability issues between Wi-Fi hotspots and packet cellular networks. In the presence of multiple wireless networks with different access costs, different areas of coverage and bandwidth, the user's choice to select a particular network can significantly impact user benefits and resource usage. We identify three major user profiles - bandwidth conscious, cost conscious and glitch conscious - and study their impact on resource utilization. Contrary to intuition, simulation experiments have shown that bandwidth conscious users may get fewer bandwidth resources compared to glitch conscious users at high mobility. Similarly, it was found that bandwidth conscious users achieve high packet delivery ratios, even while incurring lower costs than cost conscious users, in certain situations. Although increasing the number of access points (APs) leads to higher packet delivery ratios, system performance degrades when the number of APs becomes very large.