This is the total transmit power this VDSL transceiver used, measured during its most recent activation (training) sequence, expressed in tenths of a dBm, reflecting how hard the modem had to drive the line to establish a working connection. Comparing this against the line's regulatory or configured maximum power ceiling shows how much headroom remains before the modem is transmitting at its limit, which matters on longer loops that require higher output power to reach acceptable SNR. A transceiver already running near its maximum allowed output power on a marginal line has little room left to compensate if the line degrades further, making it a candidate for closer monitoring than a line running well below its power ceiling.