The secondparagraph of 2.3D.151 (1 0/92) contains the following text:
The pattern may be generated in a twenty-stage shift register whose 17th and 20th stage outputs are
added in a modulo-two addition stage, and the result is fed back to the input of th
ITU-T O.151-1992 history
1992ITU-T O.151-1992 ERROR PERFORMANCE MEASURING EQUIPMENT OPERATING AT THE PRIMARY RATE AND ABOVE