
PASS Application data is 125 byte which means any 'Extended payload length' field isn't used at all. 
PASS Application data is 126 byte which starts to use the 16 bit 'Extended payload length' field. 
PASS Application data is 0xFFFF byte which means the upper bound of the 16 bit 'Extended payload length' field. 
PASS Application data is (0xFFFF + 1) byte which starts to use the 64 bit 'Extended payload length' field