Patent ID: 7161960

Claim:
In a packet communication system having a first communication station for sending data formatted into a packet-formatted data packet pursuant to a selected packet formatting protocol upon a communication channel, the packet-formatted data packet having a header part and a payload part, an improvement of apparatus for selectably protecting a first selected portion of the checksum-data packet by a first selected checksum at least a second selected portion of the data packet by a second selected checksum, said apparatus comprising: a formatter coupled to receive the data to be sent by the sending station, said formatter for formatting the data pursuant to the selected packet data protocol to form the packet-formatted data packet therefrom, the data packet selectably having a first portion identifying the first selected portion and indicia associated with the first selected checksum and selectably having at least a second portion identifying at least the second selected portion and indicia associated with the at least the second selected checksum; and a selector coupled to said formatter, said selector selectably for selecting the first portion and the first selected checksum and selectably for selecting the second portion and the at least the second checksum.