Tunnelling the internet

Despite a considerable increase in the capacity of the Internet, regional congestion is still an issue at certain times of day. Dimensioning the system to provide minimal delay under these transient conditions would be uneconomical, particularly as various forms of application data are more or less sensitive to these delays, as are different end-users. We therefore investigate a scheme that allows end-users to selectively exploit a sequence of mini tunnels along a path from their origin to a chosen destination. We assume the availability of such tunnels is advertised centrally through a broker, with the cooperation of the Autonomous System (AS) domain operators, allowing end-users to use them if so desired. The closest analogy this scheme is that of a driver choosing to use one or more toll roads along a route to avoid potential congestion or less desirable geographic locations. It thus takes the form of a type of loose source routing. Furthermore, the approach avoids the need for inter-operator cooperation, although such cooperation would provide a means of extending tunnels across AS peers. In this paper we explore the benefit in terms of delay reduction for a given concentration of tunnel presence within a portion of the Internet. We show that a relatively small number of tunnels may be sufficient to provide worthwhile improvements in performance for some users at least. We consider both the case when tunnels are randomly distributed, and when they are provided close to an AS domain of interest, where traffic congestion is more likely. In this latter case, even a relatively small number of tunnels can provide a notable benefit to a reasonable number of users spread across a large region.