System and method to insert a TCP checksum in a protocol neutral manner
US6728929B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Feb 16, 2001 |
| Grant date | Apr 27, 2004 |
| Priority date | — |
| Expiry date | Apr 22, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L1/0072
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A method and apparatus for calculating and inserting a TCP checksum neutralizing value into a network data packet in a manner which minimizes storage requirements and processing time used to process the data packet. In one embodiment, a checksum is calculated as a data packet is being received, up to the checksum field. The calculated checksum is then inserted into the checksum field. Then the remaining fields used to calculate the TCP checksum are summed. The inverse of this sum is then stored in a normally unused portion of the payload portion of the data packet near the end of the packet. When the packet is received and the TCP checksum is calculated, since the inverse of the fields which were not used to calculated the checksum in the TCP header is in the payload portion, their contribution to the checksum is negated so that a comparison of the calculated checksum and the stored TCP checksum will match, assuming the packet was properly received.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.