Compression of forwarding decisions in a network device
US6343078B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | May 12, 2000 |
| Grant date | Jan 29, 2002 |
| Priority date | — |
| Expiry date | May 12, 2020 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L49/354
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
An apparatus for and a method of compressing the forwarding decision for a frame within a network device. A forwarding decision is compressed yielding a forwarding pointer that occupies far less memory space than the corresponding output port vector. The compressed forwarding pointers are stored in a forwarding table that is accessed using a hash function. A forwarding CAM is used to resolve conflicts in the hash table. The output port vectors are stored in an output port vector table that comprises a relatively small number of possible combinations of the port vector. A forwarding decision is made for each received frame by a forwarding processor in the device. The forwarding decision is represented by a compressed forwarding pointer that is stored in a table and associated with the received frame. At some later point in time, the frame is output to one or more destination ports in accordance with a corresponding output port vector. At this time, the compressed forwarding decision is expanded to an output port vector using the relatively small port vector table. In this fashion, large memories to store the actual output port vector are not needed since only a relatively short poin…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.