This read-only floating-point object reports the terminal's cumulative Bit Error Rate measured continuously since the link last started up, as opposed to a windowed or interval-based figure. An engineer checks this to get the overall long-run quality picture of the current link session. For example, a high wvlinkBER value even though the interval-based BER counters look clean would suggest a large one-time burst of errors happened earlier in this link's uptime, since the cumulative figure carries that history forward.