What value of Latency to set
According to the SRT documentation, Latency is calculated as 2*RTT. RTT is measured using the Ping command, i.e. using the Ping command, you measure the time it takes for a packet to travel from an encoder to a decoder. Unfortunately, it is not always possible to use this command. Therefore, the Latency parameter must be fitted together. We recommend setting Latency to 300 mc (with a good connection) and 2000 mc (with an average connection).
Please note that in our "free" encoders there is a special mode for measuring SRT speed. For example, in the StreamToStudio mobile app, it looks like this: