ROUTER DEVICE

• Main Authors: GOTO TATSUYOSHI, NAKAZATO JUNICHI, TAKAHASHI JUNICHI, KAWANO TOMOHIDE
• Format: Patent
• Language: English
• Published: 16.05.2000
• Edition: 7
• Subjects: ELECTRIC COMMUNICATION TECHNIQUE; ELECTRICITY; SELECTING; TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHICCOMMUNICATION

PROBLEM TO BE SOLVED: To transfer a packet at a high speed by determining an entry to retrieve, based on a mask value obtained by subtracting one bit, to retrieve again at the time of not reaching a prescribed minimum number of bits and retrieving a mask value in parallel with subtracting one by one bit until retrieving a coinciding address. SOLUTION: A sub-network mask is set to a destination IP address and a hush value is calculated from a destination IP address. Next, an entry to retrieve is fixed from this hush value to retrieve a retrieving table (No.2) 300. In a case when the entry fixed by the hush value does not hit, a new hush value is calculated by reducing one bit from a mask value to determine and retrieve a new entry from the obtained hush value. In a case when the entry hits, a receiving packet is transferred to a transferring destination port corresponding to this entry and the address IP address of the receiving packet is registered to the retrieving table (No.1).