This reports whether the CBR card detected cells arriving out of their expected sequence for longer than the Bellcore-defined extended period, which for CBR/AAL1 traffic means reordering or loss severe enough to corrupt the reconstructed bit stream. An admin sees error(2) here specifically on circuits carrying TDM traffic, such as emulated E1, telling them the reordering is severe enough to cause audible glitches rather than just a rising counter. For example, a CBR circuit routed across a congested trunk carrying cells from multiple interleaved VCs might briefly show error before self-clearing once congestion passes.