On the battlefield I know about drums and such to deliver marching orders, but large armies spread over large areas, like every huge logistical feat relies on communication, I'm interested in that side of things today.

How did armies during Revolutionary France/Napoleonic Wars communicate with allied armies? How would Napoleon know about things happening in Paris when off campaigning with his army? How did a wagon train know where to deliver X amount of food?

I know a little bit about telegraph semaphore's but those have significant drawbacks, but they do show someone was trying to do better than a coded message in a riders satchel. but just how sophisticated was communication at this time?