Patent ID: 6262985
Filing Date: 2001-07-17
Classification: H04L,H04Q

Abstract:
A method of translating any of a full range of external identifiers into an internal identifier, the method comprising:providing a final look-up table (LUT) that has an internal identifier in each of its entries, that is divided into a plurality of pages, and that allows access to a given entry upon receiving a base-address that specifies the page of the entry and an offset-address that specifies the position of the entry within the page;providing an initial look-up table (LUT) that has in each of its entries a base-address of a page of the final LUT;dividing an inputted external identifier into a plurality of fields;inputting the contents of a subset of the plurality of fields, the subset being associated with the internal identifiers inside a specific page of the final LUT, as a given address into the initial look-up table to obtain the base-address of the specific page;determining an offset address from the contents of the field or fields of the external identifier not sent into the initial LUT, the offset address being limited to a respective value for each base address;adding the base-address of the specific page obtained from the inputting step to the offset-address to obtain a resulting sum, and using the resulting sum as an address into the final LUT; andreading the entry of the final LUT referenced by the resulting sum to obtain the internal identifier, the internal identifier having a range which is smaller than the full range of the external identifiers.