# US 11,909,654 B2 · Optimizing segment routing paths using segment identifiers > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,909,654 B2 - Document ID: US11909654B2 - Status: Granted - Kind: B2 - Application number: 17/859,664 - Filed: 2022-07-07 - Published: 2022-10-27 - Granted: 2024-02-20 - Earliest claimed: 2020-11-30 - Assignees: Cisco Technology, Inc. - Applicants: Cisco Technology, Inc. - Inventors: Amila Pradeep Kumara Tharaperiya Gamage; Darren Russell Dukes - Web page: https://patentgrep.com/patent/US11909654B2 ## CPC - H04L 12/4625: {Single bridge functionality, e.g. connection of two networks over a single bridge} - H04L 47/2441: relying on flow classification, e.g. using integrated services [IntServ] - H04L 45/123: {Evaluation of link metrics (techniques for monitoring network metrics H04L43/08)} - H04L 45/124: {using a combination of metrics} - H04L 45/38: {Flow based routing} - H04L 45/50: using label swapping, e.g. multi-protocol label switch [MPLS] - H04L 45/507: {Label distribution} - H04L 47/2483: involving identification of individual flows - H04L 47/28: in relation to timing considerations - H04L 47/33: using forward notification - H04L 2101/375: Access point names [APN] - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract Techniques for optimizing segment routing (SR) paths using segment identifiers (SIDs) are disclosed, including determining a packet is to be sent from a first node to a second node of a network using an SR method. The techniques may also include determining a segment quantization factor that is representative of a first number of SIDs that are included in a segment quantization interval. Based at least in part on the segment quantization factor and a cost constraint, an SR path defined by a second number of SIDs to send the packet may be determined. The second number of SIDs may be associated with maximizing the SIDs included in individual ones of segment quantization intervals. The techniques further include modifying the packet to include at least the second number of SIDs and causing the packet to flow from the first node to the second node via the SR path. ## Claims ### Claim 1 A method comprising: determining that a packet is to be sent from a first node of a network to a second node of the network using a segment routing (SR) method; determining an SR path between the first node and the second node, the SR path defined by a total number of segments that (i) reduces a cost associated with the SR path below a threshold and (ii) maximizes a number of segment identifiers (SIDs) included in a segment quantization interval associated with the network; and causing the packet to flow from the first node to the second node via the SR path. ### Claim 2 (depends on 1) The method of claim 1, wherein the total number of segments is at least one of equal to or a multiple of the number of SIDs included in the segment quantization interval. ### Claim 3 (depends on 1) The method of claim 1, wherein the segment quantization interval is equal to at least one of a number of micro segment identifiers (SIDs) containable within a micro-SID carrier or a number of SIDs associated with a single pass in a forwarding application-specific integrated circuit (ASIC). ### Claim 4 (depends on 1) The method of claim 1, wherein determining the SR path based at least in part on the segment quantization interval comprises determining the SR path such that a number of segment identifiers involved with sending the packet from the first node to the second node is maximized based at least in part on the segment quantization interval. ### Claim 5 (depends on 4) The method of claim 4, further comprising modifying the packet to include the number of segment identifiers to send the packet from the first node to the second node. ### Claim 6 (depends on 1) The method of claim 1, wherein determining the SR path is further based at least in part on a cost constraint. ### Claim 7 (depends on 6) The method of claim 6, wherein determining the SR path based at least in part on the segment quantization interval and further based at least in part on the cost constraint comprises determining the SR path such that: a number of segment identifiers (SIDs) involved with sending the packet from the first node to the second node is maximized based at least in part on the segment quantization interval; and a path cost associated with the SR path is less than or equal to the cost constraint. ### Claim 8 (depends on 6) The method of claim 6, wherein the cost constraint is associated with at least one of: a latency metric; an Interior Gateway Protocol (IGP) metric; or a Traffic Engineering (TE) metric. ### Claim 9 A system comprising: one or more processors; and one or more non-transitory computer-readable media storing instructions that, when executed, cause the one or more processors to perform operations comprising: determining that a packet is to be sent from a first node of a network to a second node of the network using a segment routing (SR) method; determining an SR path between the first node and the second node, the SR path defined by a total number of segments that (i) reduces a cost associated with the SR path below a threshold and (ii) maximizes a number of segment identifiers (SIDs) included in a segment quantization interval associated with the network; and causing the packet to flow from the first node to the second node via the SR path. ### Claim 10 (depends on 9) The system of claim 9, wherein the total number of segments is at least one of equal to or a multiple of the number of SIDs included in the segment quantization interval. ### Claim 11 (depends on 9) The system of claim 9, wherein the segment quantization interval is equal to at least one of a number of micro segment identifiers (SIDs) containable within a micro-SID carrier or a number of SIDs associated with a single pass in a forwarding application-specific integrated circuit (ASIC). ### Claim 12 (depends on 9) The system of claim 9, wherein determining the SR path based at least in part on the segment quantization interval comprises determining the SR path such that a number of segment identifiers involved with sending the packet from the first node to the second node is maximized based at least in part on the segment quantization interval. ### Claim 13 (depends on 12) The system of claim 12, the operations further comprising modifying the packet to include the number of segment identifiers to send the packet from the first node to the second node. ### Claim 14 (depends on 9) The system of claim 9, wherein determining the SR path is further based at least in part on a cost constraint. ### Claim 15 (depends on 14) The system of claim 14, wherein determining the SR path is based at least in part on the segment quantization interval and further based at least in part on the cost constraint comprises determining the SR path such that: a number of segment identifiers (SIDs) involved with sending the packet from the first node to the second node is maximized based at least in part on the segment quantization interval; and a path cost associated with the SR path is less than or equal to the cost constraint. ### Claim 16 (depends on 14) The system of claim 14, wherein the cost constraint is associated with at least one of: a latency metric; an Interior Gateway Protocol (IGP) metric; or a Traffic Engineering (TE) metric. ### Claim 17 One or more non-transitory computer-readable media storing instructions that, when executed, cause one or more processors to perform operations comprising: determining that a packet is to be sent from a first node of a network to a second node of the network using a segment routing (SR) method; determining an SR path between the first node and the second node, the SR path defined by a total number of segments that (i) reduces a cost associated with the SR path below a threshold and (ii) maximizes a number of segment identifiers (SIDs) included in a segment quantization interval associated with the network; and causing the packet to flow from the first node to the second node via the SR path. ### Claim 18 (depends on 17) The one or more non-transitory computer-readable media of claim 17, wherein the total number of segments is at least one of equal to or a multiple of the number of SIDs included in the segment quantization interval. ### Claim 19 (depends on 17) The one or more non-transitory computer-readable media of claim 17, wherein the segment quantization interval is equal to at least one of a number of micro segment identifiers (SIDs) containable within a micro-SID carrier or a number of SIDs associated with a single pass in a forwarding application-specific integrated circuit (ASIC). ### Claim 20 (depends on 17) The one or more non-transitory computer-readable media of claim 17, wherein a number of segment identifiers involved with sending the packet from the first node to the second node is maximized based at least in part on the segment quantization interval.