I shouldn't have said "a few seconds all the way to france." I should have said a few seconds to the First Downlink Ground Station.
I receive ACARS messages on my SITA printer at work. One message is sent when the aircraft is airbourne. It is sent by VHF to the local receiving station, then transmitted 800 miles to our home base. The Ops computor then sends out the auto departure message that comes back 800 miles and clacks out on my printer. As I hear this message four times a day, I know what it sounds like. Yes the clackety clack of the printer tells me it is a dep message. I look out of my window and see the aircraft retracting irs gear as it flies past. These are very small data packets, and they move fast.