Abstract: An IP communication architecture between a ground computer connected to a main router and a mobile computer which is located on board a train and which is connected to a mobile router on the train. The architecture comprises at least one infrastructure comprising the base stations equipped with radio communication devices and base routers on the ground which are connected to the infrastructure. Each mobile router comprises: a radio communication means suitable for establishing a wireless link with one of the base stations of the infrastructure, storage means comprising the IP address of the base routers connected to the infrastructure, and connection means for initiating a connection with a base router on the basis of the list of base routers, after a wireless link has been established.