# US 12,001,255 B2 · Persistent Power over Ethernet > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,001,255 B2 - Document ID: US12001255B2 - Status: Granted - Kind: B2 - Application number: 17/302,641 - Filed: 2021-05-07 - Published: 2021-10-21 - Granted: 2024-06-04 - Earliest claimed: 2014-09-02 - Assignees: Cisco Technology, Inc. - Applicants: Cisco Technology, Inc. - Inventors: Ahmed Faraz; Krishna Kumar Vavilala; Kabiraj Sethi - Web page: https://patentgrep.com/patent/US12001255B2 ## CPC - G06F 1/266: {Arrangements to supply power to external peripherals either directly from the computer or under computer control, e.g. supply of power through the communication port, computer controlled power-strips} - H04L 12/10: Current supply arrangements - H04L 12/40045: {Details regarding the feeding of energy to the node from the bus} - H04L 12/413: with random access, e.g. carrier-sense multiple-access with collision detection [CSMA-CD] - G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract Embodiments described herein improve availability of a power plane in a network device by using a PoE manager that is separate from an operating system in the network device. For example, when the operating system (or a PoE application executing in the operating system) becomes unavailable, either because of failure or system upgrade, the PoE manager continues managing a power plane in the network device such that connected PDs continue to receive DC power. Stated differently, by using a PoE manager that is separate from the operating system, there is no fate sharing between the PoE manager and the operating system. If the operating system is unavailable, the PoE manager continues to provide the same power allotment to the PDs. As such, updates and failures which previously made the power plane unavailable no longer affect the power supplied to the PDs. ## Claims ### Claim 1 A Power-over-Ethernet (PoE) enabled network device, comprising: power sourcing equipment (PSE) configured to provide DC power to a powered device (PD); an operating system configured to: maintain a data plane for routing data; and maintain, at least in part, a power plane for supplying the DC power to the PD by: communicating with the PD to negotiate an allocation of power to the PD; and determining a power allocation for the PD; a PoE manager, separate from the operating system, configured to: maintain, at least in part, the power plane; receive, from the operating system, the power allocation for the PD; control the PSE to deliver power over a PoE connection to the PD based on the power allocation for the PD received from the operating system separate from the PoE manager; when the operating system is rebooting, monitor the PoE connection, control the PSE to deliver power over the PoE connection to the PD based on the power allocation for the PD received from the operating system separate from the PoE manager, and cause the PSE to stop delivering power over the PoE connection based on a condition detected by the PoE manager independently from the operating system; and log a PoE event occurring during a time the operating system is rebooting and wherein the logged PoE event is accessible to the operating system when the operating system completes rebooting. ### Claim 2 (depends on 1) The network device of claim 1, wherein the condition comprises a PD consuming more power than a corresponding allocation. ### Claim 3 (depends on 1) The network device of claim 1, further comprising: a first processor configured to execute the operating system; and a second processor configured to execute the PoE manager, wherein the first and second processors are operated independently such that when the first processor is unavailable, the second processor continues to execute the PoE manager. ### Claim 4 (depends on 1) The network device of claim 1, wherein the operating system and the PoE manager are executed as separate processes by a same processor and wherein, when the operating system is rebooting, the same processor is configured to continue to the PoE manager such that DC power is supplied to the PD. ### Claim 5 (depends on 1) The network device of claim 1, further comprising a shared memory accessible by both the operating system and the PoE manager, wherein the operating system and PoE manager are configured to exchange information related to managing the power plane using the shared memory. ### Claim 6 A method comprising: providing, by PSE, DC power to a PD; maintaining, by an operating system, a data plane for routing data; maintaining, by the operating system, at least in part, a power plane for supplying the DC power to the PD by: communicating with the PD to negotiate an allocation of power to the PD; and determining a power allocation for the PD; maintaining, by a PoE manager separate from the operating system, at least in part, the power plane; receiving, at the PoE manager and from the operating system, the power allocation for the PD; controlling, by the PoE manager, the PSE to deliver power over a PoE connection to the PD based on the power allocation for the PD received from the operating system; when the operating system is rebooting, monitoring, by the PoE manager, the PoE connection, controlling the PSE to deliver power over the PoE connection to the PD based on the power allocation for the PD received from the operating system separate from the PoE manager, and causing the PSE to stop delivering power over the PoE connection based on a condition detected by the PoE manager independently from the operating system; and logging, by the PoE manager, a PoE event occurring during a time the operating system is unavailable, wherein the logged PoE event is accessible to the operating system when the operating system becomes available. ### Claim 7 (depends on 6) The method of claim 6, wherein the condition comprises a PD consuming more power than a corresponding allocation. ### Claim 8 (depends on 6) The method of claim 6, further comprising: executing, by a first processor, the operating system; and executing, by a second processor, the PoE manager, wherein the first and second processors are operated independently such that when the first processor is unavailable, the second processor continues to execute the PoE manager. ### Claim 9 (depends on 6) The method of claim 6, wherein the operating system the PoE manager are executed as separate processes by a same processor and wherein, when the operating system is unavailable, the same processor is configured to continue to the PoE manager such that DC power is supplied to the PD. ### Claim 10 (depends on 6) The method of claim 6, further comprising exchanging, by the operating system and the PoE manager, information related to managing the power plane using a shared memory accessible by both the operating system and the PoE manager. ### Claim 11 An apparatus comprising: PSE configured to provide DC power to PDs; an operating system configured to maintain a data plane for routing data, wherein the operating system comprises a PoE application configured to maintain, at least in part, a power plane for supplying the DC power to the PDs by: communicating with one or more PDs to negotiate an allocation of power to the one or more PDs respectively; and determining a power allocation for the one or more PDs; a PoE manager, separate from the operating system, configured to: maintain, at least in part, the power plane; control the PSE to deliver power over one or more PoE connections to the one or more PDs based on the power allocation determined by the operating system; cause the PSE to stop delivering power over a first PoE connection of the one or more PoE connections based on a detected condition, wherein when the operating system or the PoE application is unavailable, the PoE manager monitors the one or more PoE connections and supplies the DC power to the PDs using the PSE; and log a PoE event occurring during a time the operating system is unavailable and wherein the logged PoE event is accessible to the operating system when the operating system becomes available. ### Claim 12 (depends on 11) The apparatus of claim 11, wherein the detected condition comprises a PD consuming more power than a corresponding allocation. ### Claim 13 (depends on 11) The apparatus of claim 11, further comprising: a first processor configured to execute the operating system and the PoE application; and a second processor configured to execute the PoE manager, wherein the first and second processors are operated independently such that when the first processor is unavailable, the second processor continues to execute the PoE manager. ### Claim 14 (depends on 11) The apparatus of claim 11, wherein the PoE application and the PoE manager are executed as separate processes by a same processor and wherein, when the PoE application is unavailable, the same processor is configured to continue to the PoE manager such that DC power is supplied to the PDs. ### Claim 15 (depends on 11) The apparatus of claim 11, further comprising a shared memory accessible by both the PoE application and the PoE manager, wherein the PoE application and PoE manager are configured to exchange information related to managing the power plane using the shared memory.