Exact topology inference for DAGs using network coding

We propose an active tomography technique for inferring directed acyclic graph (DAG) logical topologies where intermediate nodes need to perform network coding. Unlike traditional traceroute-based techniques, our technique requires only unidirectional communication on each link, and does not require the nodes to reveal their unique identities. Also, unlike other recent techniques, our technique requires a single probing experiment with only one probe packet flowing on each link and the deterministic outcome always gives the exact logical topology. As a preparation, we first present two network coding based topology inference schemes for tree topologies which are also of independent interest.