Hash functions for applications such as network address lookup
US7990973B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 13, 2008 |
| Grant date | Aug 2, 2011 |
| Priority date | — |
| Expiry date | Sep 1, 2029 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L45/74591
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
In one embodiment, IP lookup into a routing table having prefixes of different prefix lengths is performed by hashing a candidate prefix value to generate a plurality of hash values, where m seed hash values are generated by applying m seed hash functions and one or more additional hash values are generated by combining two or more of the seed hash values in different ways, e.g., using a bit-wise XOR function. The hash values are used to perform membership probes into a Bloom filter programmed with the prefixes corresponding to all of the different prefix lengths in the routing table without having to expand any of the prefixes programmed into the Bloom filter.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.