The DS3 AIS is framed with 'stuck stuffing.' This implies that it has a valid M-subframe alignments bits, M-frame alignment bits, and P bits. The information bits are set to a 1010... sequence, starting with a one (1) after each M-subframe alignment bit, M-frame alignment bit, X bit, P bit, and C bit. The C bits are all set to zero giving what is called 'stuck stuffing.' The X bits are set to one. The DS3 AIS defect is declared after DS3 AIS is present in contiguous M-frames for a time equal to or greater than T, where 0.2 ms <= T <= 100 ms. The DS3 AIS defect is terminated after AIS is absent in contiguous M-frames for a time equal to or greater than T. The E3 binary content of the AIS is nominally a continuous stream of ones. AIS detection and the application of consequent actions, should be completed within a time limit of 1 ms.