# US 10,310,944 B2 · Phased network formation for power restoration > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,310,944 B2 - Document ID: US10310944B2 - Status: Granted - Kind: B2 - Application number: 15/696,851 - Filed: 2017-09-06 - Published: 2017-12-21 - Granted: 2019-06-04 - Earliest claimed: 2014-11-07 - Assignees: Cisco Technology, Inc. - Applicants: Cisco Technology, Inc. - Inventors: Jonathan W. Hui; Jean-Philippe Vasseur; Wei Hong - Web page: https://patentgrep.com/patent/US10310944B2 ## CPC - H04L 45/02: Topology update or discovery - G06F 11/0709: {in a distributed system consisting of a plurality of standalone computer nodes, e.g. clusters, client-server systems} - G06F 11/0793: {Remedial or corrective actions (recovery from an exception in an instruction pipeline G06F9/3861; by retry G06F11/1402; for recovering from a failure of a protocol instance or entity H04L69/40)} - G06F 11/1415: {at system level} - H04L 45/28: using route fault recovery - G06F 11/1469: {Backup restoration techniques} - G06F 2201/805: Real-time - H04L 43/06: Generation of reports - H04L 45/48: Routing tree calculation - H04L 49/00: Packet switching elements - H04L 69/40: for recovering from a failure of a protocol instance or entity, e.g. service redundancy protocols, protocol state redundancy or protocol service redirection (management of faults, events, alarms or notifications in data switching networks H04L41/06) - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) - G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) ## Abstract In one embodiment, a device receives a router advertisement message after a power outage event in a network. The device joins the network, in response to receiving the router advertisement message. The device sends a power restoration notification message via the network. The device selectively delays a disconnected node from joining the network. ## Claims ### Claim 1 A method comprising: providing, by a device in a Directed Acyclic Graph (DAG) network, a first instruction to a first node in the network that causes the first node to selectively delay a disconnected node from joining the network by entering the first node into a leaf mode of operation, in response to the first node receiving the first instruction from the device, wherein the first node is configured to prevent advertising a presence of the network to the disconnected node while the first node is in the leaf mode of operation, wherein the first instruction comprises a threshold number of router advertisement messages that the first node must receive before joining the network or advertising a presence of the network to the disconnected node; determining, by the device, whether formation of the network should continue being delayed; and providing, by the device, a second instruction to the first node that causes the first node to stop delaying the disconnected node from joining the network, based on a determination that formation of the network should no longer be delayed. ### Claim 2 (depends on 1) The method as in claim 1, wherein the first instruction causes the first node to adjust an amount of power used by the first node to advertise a presence of the network to the disconnected node. ### Claim 3 (depends on 1) The method as in claim 1, wherein determining whether formation of the network should continue being delayed comprises: determining, by the device, whether a location of a power outage can be identified. ### Claim 4 An apparatus, comprising: one or more network interfaces to communicate with a Directed Acyclic Graph (DAG) network; a processor coupled to the one or more network interfaces and configured to execute a process; and a memory configured to store the process executable by the processor, the process when executed operable to: provide a first instruction to a first node in the network that causes the first node to selectively delay a disconnected node from joining the network by entering the first node into a leaf mode of operation, in response to the first node receiving the first instruction from the device, wherein the first node is configured to prevent advertising a presence of the network to the disconnected node while the first node is in the leaf mode of operation, wherein the first instruction comprises a threshold number of router advertisement messages that the first node must receive before joining the network or advertising a presence of the network to the disconnected node; determine whether formation of the network should continue being delayed; and provide a second instruction to the first node that causes the first node to stop delaying the disconnected node from joining the network, based on a determination that formation of the network should no longer be delayed. ### Claim 5 (depends on 4) The apparatus as in claim 4, wherein the first instruction causes the first node to adjust an amount of power used by the first node to advertise a presence of the network to the disconnected node. ### Claim 6 (depends on 4) The apparatus as in claim 4, wherein the apparatus determines whether formation of the network should continue being delayed by: determining whether a location of a power outage can be identified. ### Claim 7 A tangible, non-transitory, computer-readable media having software encoded thereon, the software when executed by a processor of a device operable to: provide a first instruction to a first node in a Directed Acyclic Graph (DAG) network that causes the first node to selectively delay a disconnected node from joining the network by entering the first node into a leaf mode of operation, in response to the first node receiving the first instruction from the device, wherein the first node is configured to prevent advertising a presence of the network to the disconnected node while the first node is in the leaf mode of operation, wherein the first instruction comprises a threshold number of router advertisement messages that the first node must receive before joining the network or advertising a presence of the network to the disconnected node; determine whether formation of the network should continue being delayed; and provide a second instruction to the first node that causes the first node to stop delaying the disconnected node from joining the network, based on a determination that formation of the network should no longer be delayed. ### Claim 8 (depends on 7) The apparatus as in claim 7, wherein the first instruction causes the first node to adjust an amount of power used by the first node to advertise a presence of the network to the disconnected node. ### Claim 9 (depends on 7) The apparatus as in claim 7, wherein the apparatus determines whether formation of the network should continue being delayed by: determining whether a location of a power outage can be identified.