# US 12,010,087 B2 · Communication device, address learning method, and program > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,010,087 B2 - Document ID: US12010087B2 - Status: Granted - Kind: B2 - Application number: 18/013,444 - Filed: 2020-07-03 - Published: 2023-09-21 - Granted: 2024-06-11 - Earliest claimed: 2020-07-03 - Assignees: Nippon Telegraph and Telephone Corporation - Applicants: Nippon Telegraph and Telephone Corporation - Inventors: Nobuhiro Shibata; Hideo Kawata; Shinichi Yoshihara - Web page: https://patentgrep.com/patent/US12010087B2 ## CPC - H04L 45/74: Address processing for routing - H04L 61/09: Mapping addresses - H04L 12/4641: {Virtual LANs, VLANs, e.g. virtual private networks [VPN] (LAN interconnection over a bridge based backbone H04L12/462; encapsulation techniques H04L12/4633; routing of packets H04L45/00; packet switches H04L49/00; virtual private networks for security H04L63/0272)} - H04L 45/66: {Layer 2 routing, e.g. in Ethernet based MAN's} - H04L 45/70: {Routing based on monitoring results} - H04L 2101/622: Layer-2 addresses, e.g. medium access control [MAC] addresses - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract An object of the present disclosure is to reduce band compression even in a case where a frame addressed to an original (overwritten) MAC is received again after a MAC address is overwritten. A communication device according to the present disclosure measures a traffic amount in any predetermined determination data unit, holds MAC entry information including the measured traffic amount and a MAC address in a MAC learning data holding unit, at the time when the number of pieces of MAC entry information held by the MAC learning data holding unit reaches an upper limit, searches for minimum MAC entry information with a minimum traffic amount from among traffic data amounts in determination data unit held by the MAC learning data holding unit, and overwrites the minimum MAC entry information obtained by search with unlearned MAC entry information that is not held by the MAC learning data holding unit. ## Claims ### Claim 1 A communication device that measures a traffic amount in any predetermined determination data unit, holds MAC entry information including the measured traffic amount and a media access control address (MAC address) in a MAC learning data holding unit, and in response to a number of pieces of MAC entry information held by the MAC learning data holding unit exceeds a limit: searches for minimum MAC entry information with a minimum traffic amount from among traffic data amounts in determination data unit held by the MAC learning data holding unit, and overwrites the minimum MAC entry information obtained by search with unlearned MAC entry information that is not held by the MAC learning data holding unit. ### Claim 2 (depends on 1) The communication device according to claim 1, wherein the communication device: measures a traffic amount for each MAC entry, holds the traffic amount for each MAC entry in the MAC learning data holding unit, searches for minimum MAC entry information with the minimum traffic amount from among traffic data amounts of respective MAC entries held by the MAC learning data holding unit, and overwrites the minimum MAC entry information obtained by search with the unlearned MAC entry information. ### Claim 3 (depends on 2) The communication device according to claim 2, wherein the communication device: measures a traffic amount of an unlearned MAC address that is not held by the MAC learning data holding unit, compares the traffic amount of the minimum MAC entry information with the traffic amount of the unlearned MAC address, and in a case where the traffic amount of the minimum MAC entry information is less than the traffic amount of the unlearned MAC address, overwrites the minimum MAC entry information with the MAC entry information of the unlearned MAC address. ### Claim 4 (depends on 1) The communication device according to claim 1, wherein the communication device measures a traffic amount for each virtual LAN (VLAN), the MAC learning data holding unit holds the traffic amount for each VLAN, minimum MAC entry information with the VLAN same as the unlearned MAC entry information and the minimum traffic amount is searched from among traffic data amounts of respective MAC entries held by the MAC learning data holding unit, and the minimum MAC entry information obtained by search is overwritten with the unlearned MAC entry information. ### Claim 5 (depends on 1) The communication device according to claim 1, wherein the MAC learning data holding unit holds a flag in association with a MAC entry of which a traffic amount is equal to or less than a predetermined traffic amount. ### Claim 6 (depends on 1) The communication device according to claim 1, wherein the traffic amount held by the MAC learning data holding unit is reset at any time interval. ### Claim 7 (depends on 1) A non-transitory computer-readable medium having computer-executable instructions that, upon execution of the instructions by a processor of a computer, cause the computer to function as the device according to claim 1. ### Claim 8 An address learning method performed by a communication device, comprising: measuring a traffic amount in any predetermined determination data unit; holding MAC entry information including the measured traffic amount and a MAC address in a MAC learning data holding unit; and in response to a number of pieces of MAC entry information held by the MAC learning data holding unit exceeds a limit: searching for minimum MAC entry information with a minimum traffic amount from among traffic data amounts in determination data unit held by the MAC learning data holding unit; and overwriting the minimum MAC entry information obtained by search with unlearned MAC entry information that is not held by the MAC learning data holding unit. ### Claim 9 (depends on 8) The method of claim 8 further comprises measuring a traffic amount for each MAC entry, holding the traffic amount for each MAC entry in the MAC learning data holding unit, searching for minimum MAC entry information with the minimum traffic amount from among traffic data amounts of respective MAC entries held by the MAC learning data holding unit, and overwriting the minimum MAC entry information obtained by search with the unlearned MAC entry information. ### Claim 10 (depends on 8) The method of claim 8 further comprises measuring a traffic amount for each virtual LAN (VLAN), the MAC learning data holding unit holds the traffic amount for each VLAN, minimum MAC entry information with the VLAN same as the unlearned MAC entry information and the minimum traffic amount is searched from among traffic data amounts of respective MAC entries held by the MAC learning data holding unit, and the minimum MAC entry information obtained by search is overwritten with the unlearned MAC entry information. ### Claim 11 (depends on 8) The method of claim 8 further comprises measuring a traffic amount of an unlearned MAC address that is not held by the MAC learning data holding unit, compares the traffic amount of the minimum MAC entry information with the traffic amount of the unlearned MAC address, and in a case where the traffic amount of the minimum MAC entry information is less than the traffic amount of the unlearned MAC address, overwrites the minimum MAC entry information with the MAC entry information of the unlearned MAC address.