Microsoft Corporation
Masked Packet Checksums For More Efficient Digital Communication

Abstract:

A masked packet checksum is utilized to provide error detection and/or error correction for only discrete portions of a packet, to the exclusion of other portions, thereby avoiding retransmission if transmission errors appear only in portions excluded by the masked packet checksum. A bitmask identifies packet portions whose data is to be protected with error detection and/or error correction schemes, packet portions whose data is to be excluded from such error detection and/or error correction schemes, or combinations thereof. A bitmask can be a per-packet specification, incorporated into one or more fields of individual packets, or a single bitmask can apply equally to multiple packets, which can be delineated in numerous ways, and can be separately transmitted or derived. Bitmasks can be generated at higher layers with lower layer mechanisms deactivated, or can be generated lower layers based upon data passed down.