Method and an apparatus to modify CRC in intermediate high speed network nodes
US5689518A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 28, 1995 |
| Grant date | Nov 18, 1997 |
| Priority date | — |
| Expiry date | Apr 28, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L2012/5674
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A method and an apparatus to calculate in an intermediate node of a communication network, the new Frame Check Sequence (FCS) appended to a data bits message which has been modified in said intermediate network node. The invention is useful for high speed networks where the transit delay needs to be optimized in the network along with the computing resources in the intermediate network nodes in terms of computer cycles and memory size. The invention consists in calculating the difference between the FCS using the difference between the modified fields in the message and the distance in bits between the end of the modified field and the end of the message; the calculation consists in differentiating `short messages` in the data flow and to provide an optimized processing for the short messages, the processing for larger messages being based on this first optimized processing. The calculation of the modified FCS comprises operations on polynomials whose coefficients belong to the Galois's Field and whose degree is limited to the one of the polynomial generator of the corresponding CRC code. The calculations include also look up operations in tables limited in size. The choice between…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.