Wiktionary
round-trip time
n. (context telecommunications English) The time elapsed for a message to a remote place and back again.
Usage examples of "round-trip time".
It took ninety-four microseconds round-trip time to the nearest point on the boundary, and a hundred and sixty microseconds to the farthest point.
The fifty days of round-trip time between us and the Herter-Halls seemed like forever.
Not with a round-trip time of seven weeks before they could get an answer.
Voyager had been designed to operate during an extended life-rime and at a great distance from Earth, with an hours-long downlink-uplink communications round-trip time.