Metrics useful in network tomography studies

To facilitate the development of statistical methods geared at analyzing data from networks, it is important to have metrics which define and measure distances between a network's links, its paths, and also between different networks. This is particularly important in the rapidly growing area of network tomography which plays a central role in studies of data, communication, and Internet traffic. We propose such metrics, outline some of their properties, and motivate them with two very recent applications. The proposed metrics are simple yet have appealing properties.