EXFO FTB-8510B Guia Del Usuario página 1293

VT Payload Pointer
The VT Payload Pointer provides a method of allowing flexible and
dynamic alignment of the VT SPE within the VT Superframe.
New Data Flag
NDF is enabled when at least 3 out of 4 bits match "1001". NDF is
disabled when at least 3 out of 4 bits match "0110".
Pointer Value
The pointer value indicates the offset between the V2 byte and the first
byte fo the VC-2/VC-1. The pointer bytes are not counted in the offset
calculation. The pointer is a binary number with the following range:
TU-2
TU-12
TU-11
SONET/SDH Application
Path
0
0
0
SDH - Lower-Order Path Overhead
Range
427
139
103
Glossary
643