I'm working on networking code for a social MMO (very low-intensity compared to an FPS) and have a question about fixed timestep.
This answer does a good job of explaining the forward-dating part of utilizing a fixed timestep, but doesn't seem to have the whole picture. If the forward-dating was meant to account for the packet getting all the way through the server to the other clients, wouldn't it have to either take into account the latency of the most latent client in order to arrive in time, or deal with it being late? I assume this is where the "simulate other clients as being a few ticks behind" concept comes in.
My question is: how is this back-dating offset calculated? Is it a single number for all other clients, or should it be variable through the server sending each client's latency? What goes into the calculation?
I would assume that the starting point is any delay caused by differences in tick rate between the game tick and networking tick (e.g. game is 60 ticks/s, network is 20 and both are in phase, you need to push clients back at least 2 ticks to let the server's network re-tick.) Is this understanding accurate?