The ping command will do that for you. Try typing

ping <server>

into a terminal and see (if you don't have a server to test on, then

ping localhost

will do). You will see a series of lines, one per packet, ending in "time=xxx" - whatever that xxx is, that's the round trip time for that packet.

When you end the ping (ctrl-c), it will even give you the minimum/average/maximum round trip times for the run (I think mdev is the calculated deviation...)