What is Echo Path Delay (EPD)?

The time in milliseconds (ms) between the incidence of a signal and the incidence of that signal's echo at a measurement point. More clearly, it is the time lapse between a transmitted signal and its reflection. This is not to be confued with an Echo Path Loss.

Echo Path Delay is the delay from some point on the signal path to the point at which the echo is occurring and back - this can be helpful in determining where in the network an echo problem is. Echo Path Delay is often measured by echo cancellers.