Round Trip Time

Round Trip Time (RTT) is the time it takes for a packet to travel from a source to a destination and back again. It provides an indication of the distance (indirectly, the number of hops) between endpoints on a network. Between two SRT devices on the same fast switch on a LAN, the RTT should be almost 0. Within the Continental US, RTT over the Internet can vary depending on the link and distance, but can be in the 60 to 100 ms range. Transoceanic RTT can be 60–200 ms or more, depending on the route.

RTT is used as a guide when configuring Bandwidth Overhead and Latency. To find the RTT between two devices, you can use the ping command. For example:

ping 198.51.100.20
56 data bytes 64 bytes from 198.51.100.20: seq=1 ttl=64
time=6.633 ms

In this example, the Response, or RTT, is 6.633 ms. You can also find the RTT for an active SRT streaming session displayed on the Statistics page.