Measuring the size of the Internet efficiently and effectively

The Internet has been growing rapidly and substantially. Being able to map the Internet or take a snapshot of its current size can help in planning the future evolution and capabilities of the Internet. Analyzing measurements acquired over long periods of time can help in understanding how the Internet evolves and is important in developing enhanced applications and new network level services.; This dissertation proposes and investigates efficient and effective methods for measuring the size of the Internet. Because of the decentralized design of the Internet, the size of the Internet cannot be evaluated analytically or numerically. Instead, we illustrate the use of sampling approaches for measuring the number of information servers on the Internet.; Measuring the size of the Internet via Monte Carlo sampling requires probing a large portion of the Internet Protocol (IP) address space to obtain an accurate estimate. However, the distribution of information servers on the Internet is highly non-uniform over the IP address space. This observation allows us to design probing strategies based on importance sampling for measuring the prevalence of an information service on the Internet that are significantly more effective than strategies relying on Monte Carlo sampling. During this research, we have performed a thorough analysis of our importance sampling based strategies and have determined an accurate estimate for the current size of the IPv4 Internet as measured by the number of web servers and FTP servers. The growth of the Internet is mapped through a periodic measurement of the prevalence of web services.