Synchronization of train motion between server and client

[Trilarion]

While reading the mailing list (#7) I realized that this is a part of Freerails I do not yet fully understand. The client gets a "train motion" directive (list of tiles, speed, acceleration, ..) and animates the train much faster than the world update rate which is fine. But how exactly do the server and the client agree on the actual position of a train?

My guess is that both must execute exactly the same point and the server must regularly send updates of the train position, so that the client can check and, if necessary, adapt to what the server says where the train is. Effectively, since the communication takes time, all the clients will lag a little bit behind the server.

One should inspect more how the current code achieves this.