text: 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.
  @cite_48: Mobile broadband networks play an increasingly important role in society, and there is a strong need for independent assessments of their robustness and performance. A promising source of such information is active end-to-end measurements. It is, however, a challenging task to go from individual measurements to an assessment of network reliability, which is a complex notion encompassing many stability and performance related metrics. This paper presents a framework for measuring the user-experienced reliability in mobile broadband networks. We argue that reliability must be assessed at several levels, from the availability of the network connection to the stability of application performance. Based on the proposed framework, we conduct a large-scale measurement study of reliability in 5 mobile broadband networks. The study builds on active measurements from hundreds of measurement nodes over a period of 10 months. The results show that the reliability of mobile broadband networks is lower than one could hope: more than 20 of connections from stationary nodes are unavailable more than 10 minutes per day. There is, however, a significant potential for improving robustness if a device can connect simultaneously to several networks. We find that in most cases, our devices can achieve 99.999 ("five nines") connection availability by combining two operators. We further show how both radio conditions and network configuration play important roles in determining reliability, and how external measurements can reveal weaknesses and incidents that are not always captured by the operators' existing monitoring tools.
  @cite_67: With broadband availability now approaching universal service in the United States, the focus on broadband metrics is shifting toward the assessment of broadband performance. The initial focus has been on the measurement and reporting of the speeds achieved by broadband services. As we develop more comprehensive and, hopefully, more meaningful frameworks for characterizing, measuring, and evaluating broadband performance, one obvious measure of merit will be reliability. In a survey, consumers identified concerns about reliability as second only to speed in importance. Moreover, as our collective reliance on broadband as critical socio-economic infrastructure increases, and as a growing range of services move into the Internet, it is reasonable to expect that demand for reliable broadband service will increase. At the same time, the growth of streaming and interactive rich multimedia, the convergence of fixed and mobile services, and the evolution of the Internet services industry pose new challenges for developing appropriate reliability metrics. While the measurement of broadband availability or speeds and the appropriate interpretation of measurement data are not simple tasks, evaluating reliability is inherently much more complex and difficult.
summary: Baltr = u @cite_48 presented a study of the reliability of four mobile broadband providers in Norway using the Nornet Edge dedicated infrastructure. This work illustrates the value of end-to-end measurements to identify failures and performance events not always captured by the operators' monitoring systems. Broadband reliability has received little attention until recently. @cite_67 discuss some of the challenges of characterizing reliability and their economic and policy implications and identify three different ways in which the reliability'' of broadband services can be measured: (1) the reliability of the service itself; (2) the reliability of network services offered by the ISP (e.g., DNS); and (3) the consistency of the service's performance. We focus on characterizing reliability in terms of the former two categories and leave the latter as future work.