# US 2023/0055091 A1 · Hierarchical resource constrained network > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2023/0055091 A1 - Document ID: US20230055091A1 - Status: Published application - Kind: A1 - Application number: 17/789,718 - Filed: 2021-01-05 - Published: 2023-02-23 - Earliest claimed: 2020-01-06 - Assignees: Essence Security International (E.S.I.) Ltd. - Applicants: Essence Security International ( E.S.I.) Ltd. - Inventors: Assi Abramovitz; Assaf Schuster; Hanan Ben Nun - Web page: https://patentgrep.com/patent/US20230055091A1 ## CPC - H04L 45/04: {Interdomain routing, e.g. hierarchical routing} - G06F 16/245: Query processing - H04L 45/42: Centralised routing - H04L 45/64: using an overlay routing layer - H04L 45/74: Address processing for routing - H04L 45/7453: using hashing - H04L 47/125: by balancing the load, e.g. traffic engineering - H04L 49/1569: {Clos switching fabrics} - H04L 67/1046: {Joining mechanisms} - H04L 67/1065: {Discovery involving distributed pre-established resource-based relationships among peers, e.g. based on distributed hash tables [DHT] (pre-configuration of logical or physical connections H04L67/1053)} - 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 System and techniques for a hierarchical resource constrained networks are described herein. Device participating in the network are divided into groups. These groups correspond to vertices in a routing graph. A leader is selected amongst the devices in each group to function as a routing node connecting to other vertices of the routing graph. Client devices attach to leaf vertices in the routing graph. To reduce overhead in placing devices into the routing pools, a distributed hash table (DHT) can be used. Here, the routing pools can be given DHT IDs based on, for example, a structure of the routing graph. Device DHT IDs are used to assign them to the routing pools based on a distance metric. Routing, in this arrangement, can use the DHT IDs to efficiently compute routing pool hops when routing messages. This arrangement works well for publication-subscription (pub-sub) services. ## Claims ### Claim 1 A machine-readable medium including instructions for dynamic routing, the machine-readable medium performed by a node, the instructions, when executed by processing circuitry, cause the processing circuitry to perform operations comprising: receiving, at a node, a distributed hash table (DFIT) query for a routing pool, the query including a DHT identifier (ID) for the routing pool, the routing pool being a vertex in a routing graph, the routing pool including one or more nodes based on a distance between the DHT lD and respective DHT IDs of the nodes; and responding to the query with a result, the result corresponding to a network address for a routing node of the routing pool. ### Claim 2 The machine-readable medium of claim I, wherein responding to the query includes determining whether the node is in the routing pool. ### Claim 3 (depends on 2) The machine-readable medium of claim 2, wherein the node is in the routing pool, and wherein the result includes the address for the routing node taken from a local store of the node. ### Claim 4 (depends on 3) The machine-readable medium of claim 3, wherein the node is the routing node for the routing pool, the node maintaining a parent connection and a set of child connections. ### Claim 5 (depends on 4) The machine-readable medium of claim 4, wherein the operations comprise receiving an attachment request from a client device that initiated the query. ### Claim at position 6 6-13. (canceled) ### Claim 14 (depends on 2) The machine-readable medium of claim 2, wherein the node is not in the routing pool, and wherein the node maintains a local cache of nodes, the local cache including respective addresses and DHT IDs for nodes stored in the local cache. ### Claim 15 (depends on 14) The machine-readable medium of claim 14, wherein the result includes a set of nodes from the local cache, the set of nodes selected based on a distance from the DHT ID in the query. ### Claim 16 (depends on 14) The machine-readable medium of claim 14, wherein the operations comprise: sorting nodes in the local cache based on distance to the DHT ID in the query; selecting a set of nodes from the local cache to minimize the distance to the DHT ID in the query; forwarding the query to the set of nodes; and extracting the routing node address from a response to the query from the set of nodes; and constructing the result to include the routing node address. ### Claim 17 (depends on 14) The machine-readable medium of claim 14. wherein the local cache is maintained via a DHT discovery procedure, the DHT discovery procedure including a local search for nodes in the routing pool, and a branch search for nodes in other routing pools corresponding to other vertices of the routing graph. ### Claim at position 11 18-26. (canceled) ### Claim 27 (depends on 1) The machine-readable medium of claim 1, wherein the routing graph implements a tree in which client devices directly connect to routing nodes in routing pools that correspond to leaf vertices when the client devices attach to the routing graph. ### Claim at position 13 28-32. (canceled) ### Claim 33 (depends on 27) The machine-readable medium of claim 27, wherein the tree is a balanced tree, and wherein DHT IDs for routing pools are based on a row and column of a corresponding vertex in the tree. ### Claim 34 (depends on 33) The machine-readable medium of claim 33, wherein the DHT ID is Key(J), where: Key(I,J) DHTHash(ServiceKey+AtLeastMaximumTreeSize+J); J=routing pool index in a tree layer; ServiceKey=an identifier unique to a service enabled by the routing graph; and AtLeastMaximumTreeSize is a value that is greater than or equal to the number of devices in support by the tree. ### Claim 35 (depends on 34) The machine-readable medium of claim 34, wherein the AtLeastMaximumTreeSize value is a ServiceSeed. ### Claim 36 (depends on 35) The machine-readable medium of claim 35, wherein the service is a topic family. ### Claim 37 (canceled) ### Claim 38 (depends on 27) The machine-readable medium of claim 27, wherein the query is generated by a client device to attach to the routing node, the DHT ID selected randomly from DHT IDs of routing pools that correspond to leaf vertices of the tree. ### Claim 39 (depends on 1) The machine-readable medium of claim 1, wherein the routing graph corresponds to a set of services of a publish-and-subscribe (pub-sub) framework, and wherein DHT IDs are computed from topic names in the set of services. ### Claim 40 (depends on 39) The machine-readable medium of claim 39, wherein the routing node services client nodes, and wherein the routing node serves as a broker for the pub-sub framework for clients serviced by the routing node. ### Claim at position 22 41-43. (canceled) ### Claim 44 (depends on 40) The machine-readable medium of claim 40 wherein the operations comprise: receiving a publish message for a topic name; obtaining a route to a second broker node to which a subscribing device is possibly attached; and transmitting the publish message to the second broker node for delivery to the subscribing device. ### Claim 45 (depends on 44) The machine-readable medium of claim 44, wherein the publish message originated from a client device, and wherein obtaining the route includes querying an organizer of the routing graph for a routing pool to which the subscribing device is attached; obtaining a second routing node for the routing pool to which the subscribing device is attached; and routing the publish message to the second routing node. ### Claim 46 (depends on 44) The machine-readable medium of claim 44, wherein obtaining the route includes calculating a routing pool DHT ID to which the subscribing device is attached from topic name specified in the publish message; locating a second routing node for the routing pool to which the subscribing device is attached using the calculated routing pool DHT ID; and routing the publish message to the second routing node. ### Claim 47 (depends on 46) The machine-readable medium of claim 46, wherein locating the second routing node includes performing a DHT search for the second routing node using the calculated routing pool DHT ID. ### Claim 48 (depends on 46) The machine-readable medium of claim 46, wherein calculatingthe routing pool DHT ID to which the subscribing device is attached includes: calculating respective routing pool DHT IDs for the topic name using a set of hashes defined for the routing graph; obtaining respective routing nodes for routing pools with the respective routing pool DFIT IDs; and routing the publish message to a respective routing node. ### Claim 49 (depends on 48) The machine-readable medium of claim 48, wherein calculating the respective routing pool MIT IDs for the topic name using the set of hashes includes calculating, obtaining a route, and routing the publish message for each hash until a positive response to routing the publish message is received, refraining from calculating any additional results once the positive response is received. ### Claim 50 (canceled)