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 includes at least one infrastructure having base stations equipped with radio communication devices and base routers on the ground which are connected to the infrastructure. Each mobile router has a radio communication device suitable for establishing a wireless link with one of the base stations of the infrastructure, a storage device means comprising having the IP address of the base routers connected to the infrastructure, and a connection device for initiating a connection with a base router on the basis of the list of base routers, after a wireless link has been established.