Burst Error Length
Counts the number of consecutive blocks in error. BLER and BERL determine the rate of error per second. BER determines the total count. Optical media has a high error rate of 1 bit out of every 100,000. Magnetic disk has a lower error rate of 1 bit out of every billion.
It contains type E21 et E31 errors, which generally indicates physical damage. E22 usually indicates the presence of dust, scratches or handling errors. This is an important parameter since it indicates the presence of physical damage with an impact on more than one block of data.