computing, by a computing system, a distribution of symbol errors in a forward error correction (FEC) frame transmitted in an optical signal;

comparing the distribution of symbol errors in the FEC frame to an expected, Poisson distribution of symbol errors;

determining, based on the comparison, that the distribution of symbol errors indicates a burst error that satisfies a threshold; and

in response to determining that the distribution of symbol errors indicates the burst error that satisfies the threshold, adjusting a control setting in an optical transceiver module to modify the optical signal.