This is a read-only integer, in milliseconds up to 128, reporting the time-domain location of the largest-amplitude echo reflector detected by the echo canceller on this call leg, with 0 meaning no reflector was found or the information isn't available. An admin uses this to pinpoint roughly how far down the line, in delay terms, the dominant source of echo is located, which can help correlate echo problems with a specific piece of equipment or cabling distance. For example, a consistently large reflector-location value on calls through a particular trunk might point an admin toward a specific piece of far-end equipment causing the echo, based on its round-trip delay.