Biblio

It is a challenge to select the most appropriate vantage points in a measurement platform with a wide selection. RIPE Atlas [2], for example currently has over 9600 active measurement vantage points, with selections based on AS, country, etc. A user is limited to how many vantage points they can use in a measurement. This is not only due to limitations the measurement platform imposes, but data from a large number of vantage points would produce a large volume to analyse and store. So it makes sense to optimize for a minimal set of vantage points with a maximum chance of observing the phenomenon in which the user is interested. Network operators often need to debug with only limited information about the problem ("Our network is slow for users in France!"). doing a minimal set of measurements that would allow testing through a wide diversity of networks could be a valuable add-on to the tools available to network operators. Given platforms with numerous vantage points, we have the luxury of testing a large set of end-customer outgoing paths. A diversity metric would allow selection of the most dissimilar vantage points, while exploring from as diverse angles as possible, even with a limited probing budget. If one finds an interesting network phenomenon, one could use the similarity metric to advantage by selecting the most similar vantage points to the one exhibiting the phenomenon, to validate the phenomenon from multiple vantage points. We propose a novel means of selecting vantage points, not based on categorical properties such as origin AS, or geographic location, but rather on topological (dis)similarity between vantage points. We describe a similarity metric across RIPE Atlas probes, and show how it performs better for the purpose of topology discovery than the default probe selection mechanism built into RIPE Atlas.

Software Defined Internet Exchange Points (SDXes) increase the flexibility of interdomain traffic delivery on the Internet. Yet, an SDX inherently requires multiple participants to have access to a single, shared physical switch, which creates the need for an authorization mechanism to mediate this access. In this paper, we introduce a logic and mechanism called FLANC (A Formal Logic for Authorizing Network Control), which authorizes each participant to control forwarding actions on a shared switch and also allows participants to delegate forwarding actions to other participants at the switch (e.g., a trusted third party). FLANC extends "says" and "speaks for" logic that have been previously designed for operating system objects to handle expressions involving network traffic flows. We describe FLANC, explain how participants can use it to express authorization policies for realistic interdomain routing settings, and demonstrate that it is efficient enough to operate in operational settings.