# US 2010/0315972 A1 · Discovery and rediscovery protocol method and system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2010/0315972 A1 - Document ID: US20100315972A1 - Status: Published application - Kind: A1 - Application number: 12/507,543 - Filed: 2009-07-22 - Published: 2010-12-16 - Earliest claimed: 2009-06-16 - Assignees: Ruggedcom Inc. - Inventors: Sidney Plotnik; Igor Peonte; Vesna Anusic; Mandeep Dhillon - Web page: https://patentgrep.com/patent/US20100315972A1 ## CPC - H04L 67/51: Discovery or management thereof, e.g. service location protocol [SLP] or web services - H04L 67/125: involving control of end-device applications over a network - Y04S 40/18: Network protocols supporting networked applications, e.g. including control of end-device applications over a network - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) - Y04S: SYSTEMS INTEGRATING TECHNOLOGIES RELATED TO POWER NETWORK OPERATION, COMMUNICATION OR INFORMATION TECHNOLOGIES FOR IMPROVING THE ELECTRICAL POWER GENERATION, TRANSMISSION, DISTRIBUTION, MANAGEMENT OR USAGE, i.e. SMART GRIDS ## Abstract A management station discovers agent devices connected to a network by broadcasting discovery messages having a session number and waiting for discovery acknowledge unicast messages from at least some of the discovery aware agent devices connected to the network. The management station receives the discovery acknowledge unicast messages from the agent devices and each message comprises the session number and an address uniquely identifying the agent device sending the discovery acknowledge unicast message. The management station then sends a unicast registration message having a sequence number based on the session number of the discovery message. At that point, the agent device will be registered permitting further communication to the registered discovery aware agent device. The management station will send, periodically, rediscovery messages having the same session number as the discovery message. The discovery aware agent devices connected to the network which have not previously responded to a discovery or rediscovery message having the same session number or have not received a registration message with a sequence number related to the session number will respond to subsequent rediscovery messages. The agent devices will not respond to subsequent rediscovery messages if the agent device has previously received a unicast registration message with a sequence number related to the session number of the multicast discovery message or the subsequent multicast rediscovery message. ## Claims ### Claim 1 A method for discovering agent devices connected to a network, said method comprising: broadcasting, from a management station, a multicast discovery message to all agent devices connected to the network, the multicast discovery message comprising a station address uniquely identifying the management station, a session number identifying a session, and command instructions to all discovery aware agent devices connected to the network to answer the discovery message; receiving, at the management station, discovery acknowledge unicast messages from at least some of the discovery aware agent devices connected to the network, the discovery acknowledge unicast messages comprising at least a device address uniquely identifying the discovery aware agent device sending the discovery acknowledge unicast message and the session number identifying the session; sending, from the management station, a unicast registration message to each discovery aware agent device from which the management station received a corresponding discovery acknowledge unicast message using the device address provided in the corresponding discovery acknowledge unicast message, said unicast registration message comprising a sequence number based on the session number identifying the session. ### Claim 2 (depends on 1) The method of claim 1 further comprising: after receiving the discovery acknowledge unicast message containing the device address uniquely identifying the discovery aware agent device sending the discovery acknowledge unicast message, registering, at the management station, the agent address of the corresponding discovery aware agent device to permit further communication to the discovery aware agent device. ### Claim 3 (depends on 1) The method as defined in claim 1 further comprising: periodically broadcasting, from the management station, rediscovery messages comprising the station address uniquely identifying the management station, the session number identifying the session and command instructions to all discovery agent devices connected to the network to answer the rediscovery message; receiving, at the management station, rediscovery acknowledge unicast messages from any discovery aware agent devices connected to the network which did not receive a unicast registration message from the management station comprising the sequence number based on the session number identifying the session, said rediscovery acknowledge unicast message containing at least the device address uniquely identifying the discovery aware agent device sending the rediscovery acknowledge unicast message and the session number identifying the session; sending, from the management station, a unicast registration message to each discovery aware agent device from which the management station received a corresponding rediscovery acknowledge unicast message using the device address provided in the corresponding rediscovery acknowledge unicast message, said unicast registration message comprising a sequence number based on the session number identifying the session; wherein the discovery aware agent device receiving a unicast registration message will not respond to any multicast rediscovery messages having the session number identifying the session. ### Claim 4 (depends on 1) The method as defined in claim 1 further comprising: broadcasting from the management station, the multicast discovery message to all agent devices connected to the network, the multicast message comprising the station address uniquely identifying the management station, a new session number, different from the session number, said new session number identifying a new session, and command instructions to all discovery aware agent devices connect to the network to answer the discovery message; receiving, at the management station, discovery acknowledge unicast messages from at least some of the discovery aware agent devices connected to the network, the discovery acknowledge unicast messages containing at least the device address uniquely identifying the discovery aware agent device sending the discovery acknowledge unicast message and the new session number identifying the new session; sending, from the management station, a unicast registration message to each discovery aware agent device from which the management station received a corresponding discovery acknowledge unicast message using the device address provided in the corresponding discovery acknowledge unicast message, said unicast registration message comprising a new sequence number based on the new session number identifying the new session; wherein each discovery aware agent receiving a unicast registration message in response to a discovery acknowledge unicast message will not respond to any multicast rediscovery messages having the new session number identifying the new session; and after receiving the discovery acknowledge unicast message containing the device address uniquely identifying the discovery aware agent device sending the discovery acknowledge unicast message and the new session number identifying the new session, registering, at the management station, the device address of the corresponding discovery aware agent device to permit further communication to the discovery aware agent device. ### Claim 5 (depends on 4) The method as defined in claim 4 further comprising: periodically broadcasting, from the management station, rediscovery messages comprising the station address uniquely identifying the management station, the new session number identifying the new session and command instructions to all discovery agent devices connected to the network to answer the rediscovery message; receiving, at the management station, rediscovery acknowledge unicast messages from any discovery aware agent devices connected to the network which did not receive a unicast registration message from the management station comprising the new sequence number based on the new session number identifying the new session, said rediscovery acknowledge unicast message containing at least the device address uniquely identifying the discovery aware agent device sending the rediscovery acknowledge unicast message and the new session number identifying the new session; sending, from the management station, a unicast registration message to each discovery aware agent device from which the management station received a corresponding rediscovery acknowledge unicast message using the device address provided in the corresponding rediscovery acknowledge unicast message, said unicast registration message comprising the new sequence number based on the new session number identifying the new session; wherein the discovery aware agent device receiving a unicast registration message will not respond to any multicast rediscovery messages having the new session number identifying the new session. ### Claim 6 (depends on 1) The method as defined in claim 1, wherein the agent devices comprise Intelligent Electronic Devices having an Ethernet interface, the device address is a Media Access Control (MAC) address, and the station address is a Media Access Control (MAC) address uniquely identifying the management station. ### Claim 7 (depends on 1) The method as defined in claim 1 wherein the unicast registration message is selected from the group consisting of get messages, set messages, data messages and identify messages. ### Claim 8 (depends on 1) The method as defined in claim 1 wherein the discovery messages, rediscovery messages and registration messages from the management station to the agent devices comprise an Ethernet protocol frame in an Ethernet protocol, said Ethernet protocol frame having a data link header comprising the station address of the management station, and, an Ethernet data portion; and wherein the Ethernet data portion comprises data for the agent devices in a further protocol, different from the Ethernet protocol. ### Claim 9 (depends on 1) The method as defined in claim 1 wherein the discovery messages, rediscovery messages and registration messages from the management station to the agent devices comprise an Ethernet protocol frame in an Ethernet protocol, said Ethernet protocol frame having a data link header comprising the station address of the management station and an Ethernet data portion; and wherein the Ethernet data portion comprises data in a first protocol frame in a first protocol, different from the Ethernet protocol, said first protocol frame having a first protocol header and a first protocol data portion, said first protocol data portion comprising a second protocol frame in a second protocol, said second protocol differing from the Ethernet protocol, said second protocol frame comprising a second protocol header and a second protocol data portion. ### Claim 10 (depends on 9) The method as defined in claim 9 wherein the second protocol is Simple Network Management Protocol (SNMP). ### Claim 11 A system for facilitating discovery of agent devices connected to a network, said system comprising: at least one discovery aware agent device connected to the network, each discovery aware agent operable to receive multicast discovery messages and unicast registration signals from the network and send to the network discovery acknowledge unicast messages comprising a device address uniquely identifying the discovery aware agent device that sends the unicast discovery acknowledge message; a management station connected to the network and operable to send unicast registration messages, multicast discovery messages and multicast rediscovery messages, said multicast discovery messages and multicast rediscovery messages comprising a station address uniquely identifying the management station and a session number uniquely identifying a session; wherein the management station broadcasts the multicast discovery message on the network and receives in response discovery acknowledge unicast messages comprising at least the agent address uniquely identifying the discovery aware agent device sending the discovery acknowledge unicast message and the session number uniquely identifying the session; and wherein the management station sends the unicast registration message to each discovery aware agent device from which the management station received a corresponding discovery acknowledge unicast message using the agent address provided in the corresponding discovery acknowledge unicast message, said registration message comprising a sequence number based on the session number uniquely identifying the session. ### Claim 12 (depends on 11) The system as defined in claim 11 wherein the management station periodically broadcasts the multicast rediscovery messages comprising the station address uniquely identifying the management station and the session number uniquely identifying the session, and, receives in response rediscovery acknowledge unicast messages from any of the at least two discovery aware agent devices connected to the network which did not previously receive a unicast registration message from the management station, the rediscovery acknowledge unicast messages containing at least the device address uniquely identifying the discovery aware agent device sending the rediscovery acknowledge unicast message, and the session number uniquely identifying the session; and wherein the management station sends the unicast registration message to each discovery aware agent device from which the management station received a corresponding rediscovery acknowledge unicast message using the agent address provided in the corresponding rediscovery acknowledge unicast message, said registration message comprising a sequence number based on this session number uniquely identifying the session. ### Claim 13 (depends on 12) The system as defined in claim 12 further comprising: a registration agent associated with the management station for registering the agent address of each discovery aware agent device from which the management station receives the corresponding discovery unicast message or the corresponding rediscovery acknowledge unicast message to permit further communication to the discovery aware agent device. ### Claim 14 (depends on 12) The system as defined in claim 12 wherein the discovery aware agent devices receiving a unicast registration message will not respond to any multicast rediscovery messages having the session number uniquely identifying the session. ### Claim 15 (depends on 11) The system as defined in claim 11, wherein the discovery aware agent devices comprise Intelligent Electronic Devices having an Ethernet interface, the device address is a Media Access Control (MAC) address, and the station address is a Media Access Control (MAC) address uniquely identifying the management station. ### Claim 16 (depends on 11) The system as defined in claim 11 wherein the unicast registration message is selected from the group consisting of get messages, set messages, data messages and identify messages. ### Claim 17 (depends on 11) The system as defined in claim 11 wherein the discovery messages, rediscovery messages and registration messages from the management station to the agent devices comprise an Ethernet protocol frame in an Ethernet protocol, said Ethernet protocol frame having a data link header comprising the station address of the management station, and, an Ethernet data portion; and wherein the Ethernet data portion comprises data for the agent devices in a further protocol, different from the Ethernet protocol. ### Claim 18 (depends on 11) The system as defined in claim 11 wherein the discovery messages, rediscovery messages and registration messages from the management station to the agent devices comprise an Ethernet protocol frame in an Ethernet protocol, said Ethernet protocol frame having a data link header comprising the station address of the management station and an Ethernet data portion; and wherein the Ethernet data portion comprises data in a first protocol frame in a first protocol, different from the Ethernet protocol, said first protocol frame having a first protocol header and a first protocol data portion, said first protocol data portion comprising a second protocol frame in a second protocol, said second protocol differing from the Ethernet protocol, said second protocol frame comprising a second protocol header and a second protocol data portion. ### Claim 19 (depends on 18) The system as defined in claim 18 wherein the second protocol is Simple Network Management Protocol (SNMP). ### Claim 20 (depends on 19) The system as defined in claim 19 wherein the unicast registration message is selected from the group consisting of get messages, set messages, data messages and identify messages. ### Claim 21 An article comprising a computer readable medium having stored thereon computer readable code which, when executed by one or more processors, facilitates discovery of agent devices connected to a network, the computer readable code comprising: instructions for causing a management station at the commencement of a session to broadcast a multicast discovery message to all agent devices connected to the network, the multicast discovery message comprising a station address uniquely identifying the management station, a session number identifying the session, and command instructions to all discovery aware agent devices connected to the network to answer the discovery message; instructions for causing the management station to receive discovery acknowledge unicast messages from at least some of the discovery aware agent devices connected to the network, the discovery acknowledge unicast messages comprising at least a device address uniquely identifying the discovery aware agent device sending the discovery acknowledge unicast message and the session number identifying the session; instructions for causing the management station to send a unicast registration message to each discovery aware agent device from which the management station received a corresponding discovery acknowledge unicast message using the device address provided in the corresponding discovery acknowledge unicast message, said unicast registration message comprising a sequence number based on the session number identifying the session.