Round Trip Time (RTT) - MDN Web Docs Glossary: Definitions of Web-related terms

Round Trip Time (RTT) is the length time it takes for a data packet to be sent to a destination plus the time it takes for an acknowledgment of that packet to be received back at the origin. The RTT between a network and server can be determined by using the ping command.

$ ping example.com
PING example.com (
216.58
.194.174)
: 56 data bytes
64
 bytes from 216.58
.194.174: icmp_seq
=
0
 ttl
=
55
 time
=
25.050 ms
64
 bytes from 216.58
.194.174: icmp_seq
=
1
 ttl
=
55
 time
=
23.781 ms
64
 bytes from 216.58
.194.174: icmp_seq
=
2
 ttl
=
55
 time
=
24.287 ms
64
 bytes from 216.58
.194.174: icmp_seq
=
3
 ttl
=
55
 time
=
34.904 ms
64
 bytes from 216.58
.194.174: icmp_seq
=
4
 ttl
=
55
 time
=
26.119 ms
--- google.com ping statistics ---
5
 packets transmitted, 5
 packets received, 0.0% packet loss
round-trip min/avg/max/stddev =
 23.781/26.828/34.904/4.114 ms