A media access controller for a network interface card accommodates protocol checksum offloads by calculating a hardware assisted checksum for an indiscriminate region of a packet including all or part of the layer 2 header, all of the layer 3 header, all of the layer 4 header, and all data payload areas...http://www.google.de/patents/US6530061?utm_source=gb-gplus-sharePatent US6530061 - Method and apparatus for offloading checksum
