Apr 04, 2017: Ansgar Fehnker: Better than B.A.T.M.A.N.

April 04, 2017Better than B.A.T.M.A.N.
Room: Hal B 2BAnsgar Fehnker

This talk considers a network routing protocol known as Better Approach to Mobile Ad hoc Networks (B.A.T.M.A.N.). The protocol has two aims: first, discovery of all bidirectional links, and second, identification of the best-next-hop to the other nodes. A key mechanism of the protocol is to flood the network at regular intervals with so-called originator messages.
I will present a formalisation of the B.A.T.M.A.N. protocol in Uppaal, and discuss several ambiguities and inconsistencies in the RFC that were discovered in the process. We developed three models models. The first implements, if possible, a literal reading of the RFC. The second model is an incremental improvement that implements the underlying concepts, if possible. This model is in some places less restrictive, and rebroadcasts more often when it helps route discovery, and will on the other hand drop more messages that might interfere with the process. The final model departs from the RFC, and changes the information that is stored about received OGMs.
We use Uppaal to compare the performance for static as well as dynamic topologies. The analysis shows that the new implementation reduces the number of suboptimal routes significantly, and recovers better from routing errors that are introduced by mobility.‚Äč