String Matching for IPv6 Routers
Authors | |
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Year of publication | 2004 |
Type | Article in Proceedings |
Conference | SOFSEM 2004 |
MU Faculty or unit | |
Citation | |
Field | Computer hardware and software |
Keywords | String matching; IPv6; IP routing; CAM; FPGA; Liberouter |
Description | String matching problem instantiates in IP routing into several operations on packet headers. Routing itself is finding the best matching prefix of a set of strings, packet filtering is a combination of prefix matching, exact, and range checks. With the increase of IPv6 importance (with its 128~bit addresses) those operations get more critical in time. Software implementations may not be powerful enough. Natural way is to move the most demanding operations into a hardware accelerator, just in the sense of hardware/software co-design ideas. String matching must be performed by hardware. Unfortunately, we have to check wider strings than today's Content Addressable Memories can hold; therefore combination of CAM and additional processing may be employed. New task for software support arises here: it has to maintain hardware lookup tables consistent with the software's ideas about routing and packet filtering. |