Coupling Vehicular Ad-hoc Networks (VANETs) of communicating vehicles with wired networks creates a difficult mix of highly mobile nodes and static infrastructure. The  IETF Mobile Ad-hoc Networks (MANET) Working Group, which tries to standardize IP routing protocols suitable for this very scenario, is currently developing DYMO, the Dynamic MANET On-demand Routing Protocol.

      In order to evaluate DYMO's performance in realistic VANET scenarios using unmodified protocols of the internet protocol suite, tools for network simulation and simulation of road traffic were coupled to model realistic scenarios. Varying traffic conditions, the available network infrastructure and parameters of DYMO helped point out approaches for improving the overall performance and revealed problems with the deployment of protocols not adapted for the use in VANETs.

      It can be shown that even for medium densities of active nodes and low network load, the amount of routing messages to be sent over the VANET leads to a drastic decrease of the perceived network quality. Using transport and routing protocols that can act both on problems perceived by lower layers and on requirements specified by higher layers therefore seems highly advisable.