# US 9,001,669 B2 · Remote stitched directed acyclic graphs > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,001,669 B2 - Document ID: US9001669B2 - Status: Granted - Kind: B2 - Application number: 13/043,111 - Filed: 2011-03-08 - Published: 2012-09-13 - Granted: 2015-04-07 - Earliest claimed: 2011-03-08 - Assignees: Cisco Technology, Inc. - Applicants: Jean-Philippe Vasseur; Shmuel Shaffer; Sandeep Jay Shetty - Inventors: Jean-Philippe Vasseur; Shmuel Shaffer; Sandeep Jay Shetty - Web page: https://patentgrep.com/patent/US9001669B2 ## CPC - H04W 40/22: using selective relaying for reaching a BTS [Base Transceiver Station] or an access point - H04L 67/12: specially adapted for proprietary or special-purpose networking environments, e.g. medical networks, sensor networks, networks in vehicles or remote metering networks - H04L 43/0823: Errors, e.g. transmission errors - H04L 43/16: Threshold monitoring - H04L 45/24: Multipath - Y04S 40/00: Systems for electrical power generation, transmission, distribution or end-user application management characterised by the use of communication or information technologies, or communication or information technology specific aspects supporting them - Y04S 40/18: Network protocols supporting networked applications, e.g. including control of end-device applications over a network - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) - 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 In one embodiment, in response to a trigger condition being detected at a particular location in a primary directed acyclic graph (DAG) in a computer network, a particular node in the primary DAG at the particular location may be determined to act as a remote stitched (RS)-DAG root for an RS-DAG at the particular location. The determined RS-DAG root may then be instructed to initiate the RS-DAG, the instructing indicating one or more properties for the RS-DAG that are based on the trigger condition and that are different from properties of the primary DAG. In another embodiment, a particular node receives instructions to initiate an RS-DAG as its RS-DAG root, initiates the RS-DAG, and relays messages of the RS-DAG with a primary root of the primary DAG. ## Claims ### Claim 1 A method, comprising: detecting, by a network device, a trigger condition at a particular location in a primary directed acyclic graph (DAG) in a computer network, wherein the primary DAG includes a root node of the primary DAG; determining, by the network device, a particular node in the primary DAG at the particular location to act as a remote stitched (RS)-DAG root for an RS-DAG at the particular location, wherein the particular node is a different node in the primary DAG than the root node of the primary DAG; instructing, by the network device, the RS-DAG root to initiate the RS-DAG, the instructing indicating one or more properties for the RS-DAG that are selected to cause additional data regarding the trigger condition to be collected within the RS-DAG and that are different from properties of the primary DAG, wherein a particular child node of the RS-DAG root in the RS-DAG has a different parent node in the primary DAG; and receiving, at the network device, a conclusion message from the RS-DAG root that aggregates the additional data regarding the trigger condition collected within the RS-DAG. ### Claim 2 (depends on 1) The method as in claim 1, wherein the trigger condition is a sensed event at the particular location. ### Claim 3 (depends on 1) The method as in claim 1, wherein the trigger condition is selected from a group consisting of: congestion at the particular location, greater than a threshold of lost packets at the particular location, and link failure at the particular location. ### Claim 4 (depends on 1) The method as in claim 1, wherein one of the one or more properties for the RS-DAG comprises one or more routing metrics for the RS-DAG. ### Claim 5 (depends on 1) The method as in claim 1, wherein one of the one or more properties for the RS-DAG comprises a list of one or more nodes in the primary DAG to specifically exclude or include from the RS-DAG. ### Claim 6 (depends on 1) The method as in claim 1, wherein one of the one or more properties for the RS-DAG comprises a length of time to maintain the RS-DAG. ### Claim 7 (depends on 1) The method as in claim 1, wherein one of the one or more properties for the RS-DAG comprises an increased sensing rate for sensor nodes in the RS-DAG. ### Claim 8 (depends on 1) The method as in claim 1, wherein one of the one or more properties for the RS-DAG comprises an objective function (OF) for the RS-DAG. ### Claim 9 (depends on 1) The method as in claim 1, wherein one of the one or more properties for the RS-DAG comprises a limited depth for the RS-DAG. ### Claim 10 (depends on 1) The method as in claim 1, wherein one of the one or more properties for the RS-DAG comprises data aggregation properties for the RS-DAG. ### Claim 11 (depends on 1) The method as in claim 1, wherein the particular location is selected from a group consisting of: a subnet mask, a list of one or more specific addresses, a geographical positioning, a particular device, and a set of devices within an identified distance from a particular device. ### Claim 12 (depends on 1) method as in claim 1, further comprising: establishing a tunnel between the root node of the primary DAG and the RS-DAG root. ### Claim 13 (depends on 1) The method as in claim 1, wherein the network device is root node of the primary DAG or a network management node in the computer network. ### Claim 14 An apparatus, comprising: one or more network interfaces to communicate in a computer network; a processor coupled to the one or more network interfaces and adapted to execute one or more processes; and a memory configured to store a process executable by the processor, the process when executed configured to: detect a trigger condition at a particular location in a primary directed acyclic graph (DAG) in the computer network, wherein the primary DAG includes a root node of the primary DAG; determine a particular node in the primary DAG at the particular location to act as a remote stitched (RS)-DAG root for an RS-DAG at the particular location, wherein the particular node is a different node in the primary DAG than the root node of the primary DAG; instruct the RS-DAG root to initiate the RS-DAG, the instructing indicating one or more properties for the RS-DAG that are selected to cause additional data regarding the trigger condition to be collected within the RS-DAG and that are different from properties of the primary DAG, wherein a particular child node of the RS-DAG root in the RS-DAG has a different parent node in the primary DAG; and receive a conclusion message from the RS-DAG root that aggregates the additional data regarding the trigger condition collected within the RS-DAG. ### Claim 15 (depends on 14) The apparatus as in claim 14, wherein the trigger condition is selected from a group consisting of: a sensed event at the particular location, congestion at the particular location, greater than a threshold of lost packets at the particular location, and link failure at the particular location. ### Claim 16 (depends on 14) The apparatus as in claim 14, wherein the one or more properties for the RS-DAG are selected from a group consisting of: one or more routing metrics for the RS-DAG, a list of one or more nodes in the primary DAG to specifically exclude or include from the RS-DAG, a length of time to maintain the RS-DAG, an increased sensing rate for sensor nodes in the RS-DAG, an objective function (OF) for the RS-DAG, a limited depth for the RS-DAG, and data aggregation properties for the RS-DAG. ### Claim 17 A tangible, non-transitory, computer-readable media having software encoded thereon, the software when executed by a processor configured to: detect a trigger condition at a particular location in a primary directed acyclic graph (DAG) in a computer network, wherein the primary DAG includes a root node of the primary DAG; determine a particular node in the primary DAG at the particular location to act as a remote stitched (RS)-DAG root for an RS-DAG at the particular location, wherein the particular node is a different node in the primary DAG than the root of the primary DAG; instruct the RS-DAG root to initiate the RS-DAG, the instructing indicating one or more properties for the RS-DAG that are selected to cause additional data regarding the trigger condition to be collected within the RS-DAG and that are different from properties of the primary DAG, wherein a particular child node of the RS-DAG root in the RS-DAG has a different parent node in the primary DAG; and receive a conclusion message from the RS-DAG root that aggregates the additional data regarding the trigger condition collected within the RS-DAG. ### Claim 18 A method, comprising: receiving, by a network device that is a particular node at a particular location in a primary directed acyclic graph (DAG) in a computer network, instructions to initiate a remote stitched (RS)-DAG by the particular node as an RS-DAG root, the instructions indicating one or more properties for the RS-DAG that are different from properties of the primary DAG, wherein the RS-DAG root is a different node in the primary DAG than a root node of the primary DAG; initiating, by the network device, the RS-DAG from the RS-DAG root to collect additional data within the RS-DAG regarding a triggering condition, wherein a particular child node of the RS-DAG root in the RS-DAG has a different parent node in the primary DAG; and relaying, by the network device, messages of the RS-DAG between the RS-DAG root and the root node of the primary DAG that include the collected additional data. ### Claim 19 (depends on 18) The method as in claim 18, wherein the one or more properties for the RS-DAG are selected from a group consisting of: one or more routing metrics for the RS-DAG, a list of one or more nodes in the primary DAG to specifically exclude or include from the RS-DAG, a length of time to maintain the RS-DAG, an increased sensing rate for sensor nodes in the RS-DAG, an objective function (OF) for the RS-DAG, and a limited depth for the RS-DAG. ### Claim 20 (depends on 18) The method as in claim 18, wherein one of the one or more properties for the RS-DAG comprises data aggregation properties for the RS-DAG, the method further comprising: aggregating the collected additional data at the RS-DAG root. ### Claim 21 (depends on 18) The method as in claim 18, further comprising: establishing a tunnel between the root node of the primary DAG and the RS-DAG root. ### Claim 22 (depends on 18) The method as in claim 18, wherein the one or more properties of the RS-DAG are based on the trigger condition, the method further comprising: performing an analysis of the trigger condition at the RS-DAG root. ### Claim 23 (depends on 18) The method as in claim 18, wherein relaying messages of the RS-DAG between the RS-DAG root and the root node of the primary DAG is in response to receiving a trigger condition notification from the root node of the primary DAG regarding the trigger condition, and wherein the RS-DAG is initiated prior to receiving the trigger condition notification. ### Claim 24 (depends on 18) The method as in claim 18, wherein receiving instructions to initiate the RS-DAG by the particular node comprises: detecting the trigger condition by the particular node, the instructions indicating one or more properties for the RS-DAG that are different from properties of the primary DAG and that are based on the trigger condition. ### Claim 25 An apparatus, comprising: one or more network interfaces to communicate as a particular node at a particular location in a primary directed acyclic graph (DAG) in a computer network, wherein the primary DAG includes a root node of the primary DAG; a processor coupled to the one or more network interfaces and adapted to execute one or more processes; and a memory configured to store a process executable by the processor, the process when executed configured to: receive instructions to initiate a remote stitched (RS)-DAG by the particular node as an RS-DAG root, the instructions indicating one or more properties for the RS-DAG that are different from properties of the primary DAG, wherein the particular node is a different node in the primary DAG than the root node of the primary DAG; initiate the RS-DAG from the RS-DAG root to collect additional data within the RS-DAG regarding a triggering condition, wherein a particular child node of the RS-DAG root in the RS-DAG has a different parent node in the primary DAG; and relay messages of the RS-DAG between the RS-DAG root and a primary root of the primary DAG that include the collected additional data. ### Claim 26 (depends on 25) The apparatus as in claim 25, wherein the one or more properties for the RS-DAG are selected from a group consisting of: one or more routing metrics for the RS-DAG, a list of one or more nodes in the primary DAG to specifically exclude or include from the RS-DAG, a length of time to maintain the RS-DAG, an increased sensing rate for sensor nodes in the RS-DAG, an objective function (OF) for the RS-DAG, a limited depth for the RS-DAG, and data aggregation properties for the RS-DAG. ### Claim 27 (depends on 25) The apparatus as in claim 25, wherein the one or more properties of the RS-DAG are based on the trigger condition, the process when executed further configured to: perform an analysis of the trigger condition. ### Claim 28 (depends on 25) The apparatus as in claim 25, wherein the process is configured to relay messages of the RS-DAG between the RS-DAG root and the primary root is in response to receiving a trigger condition notification from the root node of the primary DAG, and wherein the process is configured to initiate the RS-DAG prior to receiving the trigger condition notification. ### Claim 29 A tangible, non-transitory, computer-readable media having software encoded thereon, the software when executed by a processor on a particular node at a particular location in a primary directed acyclic graph (DAG) in a computer network configured to: receive instructions to initiate a remote stitched (RS)-DAG by the particular node as an RS-DAG root, the instructions indicating one or more properties for the RS-DAG that are different from properties of the primary DAG, wherein the RS-DAG root is a different node in the primary DAG than a root node of the primary DAG; initiate the RS-DAG from the RS-DAG root to collect additional data within the RS-DAG regarding a triggering condition, wherein a particular child node of the RS-DAG root in the RS-DAG has a different parent node in the primary DAG; and relay messages of the RS-DAG between the RS-DAG root and the root node of the primary DAG that include the collected additional data.