The knowledge of the internal structure or map of the Internet is crucial in order to be able to face the challenges of the Future Internet and to better understand its main features such as resilience, performance, criticality, and efficiency.

Although we know that the Internet has a markedly hierarchical representation (its domain names are arranged like the “nodes” of a “reverse” tree with roots and leaves), but its internal structure is virtually unknown because it is largely hidden from us. Most of the companies offering Internet services (such as Telecom Italy, Vodafone) do not provide any topological data on the network they own and administer nor on the connections between them. The reasons for this behavior are essentially economic, related to business and competition.

Isolario freccia is aimed at building accurate regional maps and focusing on the part of the Internet infrastructure that is of interest to Italian users.
The observation points chosen by Isolario to measure the topological characteristics of the net are smartphones and tablets, the fundamental components of the Future Internet.

The Portolan freccia app was developed for this purpose. It takes its name from the ancient Portolan charts, manuals for naval navigation used in the Middle Ages, updated and compiled on the basis of the relationships and experiences of sailors.