Efficient implementation of the OSI transport protocol checksum algorithm using 8/16-bit arithmetic
Alistair Cockburn · ACM SIGCOMM Computer Communication Review · 1987
The checksum algorithm recommended in the OSI transport-protocol specfications is an arithemetic checksum algorithm which makes heavy use of base-255 addition. In this technical note, an efficient implementation of the recommended checksum algorithm is derived, using 8-bit unsigned addition as the base for an inexpensive modulo-255 addition.