A method (200) and an apparatus (500) in a packet switched data transfer system for processing header bits and payload bits in a frame of bits are disclosed. The header bits are classified into a first predetermined class of bits and into a second predetermined class of bits (204), the payload bits are classified into the first predetermined class of bits and into the second predetermined class of bits (206), the first predetermined class of bits are processed in accordance with a first predetermined mechanism (208), and the second predetermined class of bits are processed in accordance with a second predetermined mechanism (210).