[jewel]

You're right, TCP/IP wouldn't work. UDP would work fine though, as well as anything lower level. You'd just continually send packets at a rate that was slow enough that there'd be no reason that the other side would drop them.

Imagine that the designers want to send information about the plane's expected arrival time to the in-flight entertainment system. You could send a packet once per minute, without any knowledge of whether or not anyone is even listening. If an update is missed, it doesn't matter since the information rapidly becomes stale.