ADJUSTING THE POWER ALLOCATION IN A POWER SUPPLY DEVICE (PSE) OF A POWER-OVER-ETHERNET SYSTEM BASED ON EVENT DETECTION AT ANOTHER PSE

Abstract

Power supply unit (PSE) (105; 302) comprising: a first port (125-N) that can be connected via a first communication link (172-1) to a powered device (PD) (174; 200; 306) to supply power to the PD via Ethernet (PoE) and to exchange communication with it; a second port (125-2) that can be connected via a second communication link (173) to an additional PSE (110; 304);and a control circuit (130) configured to, in a state where the PD is connected to the first terminal and the additional PSE is connected to the second terminal: exchange a first set of transport layer protocol communications with the additional PSE, the additional PSE being connected to the PD to provide PoE for the PD, wherein the first set of transport layer protocol communications includes: a first communication (313) from the PSE to the additional PSE, which includes a first PoE configuration field specifying a PoE configuration of the PSE; and a second communication (315) from the additional PSE to the PSE, which includes a second PoE configuration field specifying a PoE configuration of the additional PSE;to generate a power availability table (327) for the PD based on the information from the first PoE configuration field and the second PoE configuration field, wherein the power availability table specifies an availability of PoE for the PD from the PSE and the additional PSE; to detect the occurrence of an event that includes at least a change in the power availability table or a change in the ability of the PSE to supply power to the PD; and, at least partially based on the occurrence of the event, to send a second set of transport layer protocol communications to the additional PSE, wherein the second set of transport layer protocol communications includes a request to the additional PSE to adjust a power allocation of the additional PSE for the PD.

Description

INTRODUCTION

[0001] Power over Ethernet (PoE) enables the transmission of data signals and power signals over a single Ethernet cable. This allows a PoE-enabled electronic device to be communicatively connected to a network and powered over the same cable, allowing greater flexibility in device placement (e.g., eliminating the need to place the device near an electrical outlet or having long power cables to reach one). Devices such as Voice over Internet Protocol (VOIP) phones, Light-Emitting Diode (LED) lights, Internet Protocol (IP) cameras, wireless access points (APs), and Bluetooth Low-Energy (BLE) beacons can be powered over PoE and can therefore be installed in locations where installing traditional power cables or power supplies would be impractical or expensive.

[0002] In a PoE system, a device that supplies power to other devices via PoE is called power sourcing equipment (PSE), and the devices that receive power from the PSE are called powered devices (PDs). The PSE also generally serves as a network element, such as a switch or router. PDs can also be network elements (e.g., a wireless access point, a PoE repeater / hub, etc.), network endpoints (e.g., a security camera, an Internet of Things (IoT) device, etc.), or any other electronic device with a PoE port. BRIEF DESCRIPTION OF THE DRAWINGS

[0003] The present disclosure can be understood from the following detailed description, either alone or in conjunction with the accompanying drawings. The drawings are included to provide a further understanding of the present disclosure and are incorporated into and constitute a part of this description. The drawings illustrate one or more examples of the present teachings and, together with the description, explain certain principles and operations. In the drawings: Fig. is a block diagram showing a PoE system with two PSEs connected to one PD, according to an example; Fig. is a block diagram showing a PD that can be connected to two PSEs in a PoE system, according to an example; Fig. is a swim lane diagram illustrating a process for managing PoE supplied to a PD that may be connected to two PSEs in a PoE system, according to an example; Fig. is a process flow diagram illustrating a method that may be performed by a PSE in a PoE system, according to one example; Fig. is another process flow diagram illustrating a method that may be performed by a PSE in a PoE system, according to one example; Fig. is a block diagram showing a storage medium that stores instructions executable by a processor of a PSE, according to an example; and Fig. is a block diagram showing a storage medium that stores instructions that can be executed by a processor of a PD, according to an example. DETAILED DESCRIPTION

[0004] Enterprise networks, data center networks (DCNs), and other types of computer networks are used to support a wide variety of organizations. Some of these networks, or portions of them, are powered by powered devices (PDs) that are supplied with power over Ethernet. Gaps in the PoE supply of such PDs can lead to outages in PD operations due to a lack of power and loss of connectivity in portions of these networks, which can prove detrimental to these organizations. Therefore, companies, universities, government agencies, hospitals, and other organizations that use such networks often place a high priority on the reliable operation of their PDs.

[0005] In an example configuration, multiple PSEs are configured to power a single PD over Ethernet for increased reliability. In such a configuration, two PSEs can be connected to a single PD, and the PD can be powered by either PSE. In some cases, the two PSEs can power the PD simultaneously, sharing the load between the two PSEs, while in other cases, only one of the PSEs powers the PD at a time. In both cases, one PSE can act as a backup for the other, so that if one PSE cannot power the PD, for example, if one PSE fails or if one of the PSEs goes for maintenance or upgrade, the other PSE can power the PD.

[0006] Generally, for a PD powered by two PSEs, one PSE can act as the main PSE and the other as the auxiliary PSE. The PD can communicate with the main PSE to advertise its power requirements. The main PSE is primarily responsible for providing power over Ethernet to the PD based on the advertised power requirements. In some cases, the PD can draw its required power from the main PSE and, in the event of a failure or lack of power from the main PSE, it can draw power from the auxiliary PSE. In other cases, the PD can draw some of its required power from the main power supply and another part of its required power from the auxiliary power supply. Which of these approaches is used to power the PD may depend on the PoE configurations of the main PSE and the auxiliary PSE. In addition, the amount of power allocated to the PD by each PSE also depends on the PoE configuration of each PSE.As used here, the PoE configuration of a PSE refers to the attributes, components, and parameters / settings of the PSE that relate to or affect the PSE's ability to provide PoE. For example, the PoE configuration of a PSE may include a firmware version of the PSE, a configuration of the PSE's ports (e.g., which ports are PoE-capable, a PoE priority of each PoE-capable port, a PoE power allocation of each PoE-capable port, etc.), a configuration of the PSE's power supply units (PSUs) (e.g., which PSUs are connected to the PSE, an output power of the PSUs, etc.), a total PoE power budget, etc. Information characteristic of or representative of the PoE configurations of the PSEs may be programmed into the main and auxiliary PSEs during installation, e.g.,by an administrator, and this information can be used by the main and auxiliary PSEs to determine whether and how much PoE power they should supply to a PD.

[0007] In a system with two PSEs supplying power to the same PD, various circumstances can affect the main PSE's ability to supply power to the PD, for example, by increasing or decreasing the power allocation to the PD. In some cases, the auxiliary PSE may be unaware of such a change in the main PSE's ability to supply power. For example, the amount of power allocated by the auxiliary PSE to the PD may remain unchanged, but due to the changed allocation by the main PSE, the total amount of power allocated to the PD may be too little or too much. Some examples of how this can happen are described below.

[0008] During operation, the PoE configuration of the main PSE may change. PoE configuration changes may include, for example, a change in the PSE's power budget, a change in the port priority of one or more ports, a change in the power allocation to one or more ports, a change in the number of PSUs connected to the PSE, and a change in the type of PSUs connected to the PSE. These PoE configuration changes in the main PSE may result in a change in the power flow from the main PSE to the PD. However, the auxiliary PSE may be unaware of such PoE configuration changes on the main PSE, so the auxiliary PSE can continue to allocate the same amount of PoE to the PD as before (i.e., the auxiliary PSE continues to allocate PoE power based on the predefined PoE configuration information programmed into it at the time of installation).For example, the auxiliary PSE may allocate more power than is needed for the PD (e.g., if the PoE configuration change caused the main PSE to supply more power), or the auxiliary PSE may allocate too little power to the PD (e.g., if the PoE configuration change caused the main PSE to supply less power). Insufficient power may prevent the PD from operating with sufficient power, resulting in power outages in the PD, and excess power allocation may cause the auxiliary PSE to lose its PoE capabilities.

[0009] In another example, the main PSE may be subject to a maintenance event or outage. Examples of a maintenance event might include a PSE firmware update or a PSE reboot. The maintenance event or outage might also result in the main PSE no longer being able to supply power to the PD.

[0010] One way to solve the problem of over- or under-powering a PD with PoE because one PSE is unaware of changes in the other PSE is for a user (e.g., a network administrator) to manually reconfigure the auxiliary PSE when a change occurs in the main PSE. For example, an administrator can monitor the power of the main PSE and the PD to detect changes in the main PSE's capability and make PoE configuration changes in the auxiliary PSE to increase the power delivered by the auxiliary PSE to the PD. Therefore, to maintain uninterrupted power supply to the PD, the administrator may need to manually detect the decrease in power flow from the main PSE to the PD and make PoE configuration changes in the auxiliary PSE to compensate for the power deficit. Because this approach depends on user intervention, it can also be error-prone.For example, it may happen that the administrator does not detect the change in a PSE in time to avoid a failure of the PD.

[0011] Another approach to solving the above problems is for the PD to detect a drop in power flow from the main power supply to the PD and request additional power from the auxiliary power supply. However, relying on the PD to detect and respond to a drop in PoE power supplied by the main power supply in this way is not always a reliable option for avoiding PoE underprovisioning, as the auxiliary power supply can acknowledge or deny the request for additional power from the PD. In one example, the auxiliary PSE can acknowledge or deny the request based on its excess power availability. For example, if the auxiliary PSE has excess power, it can acknowledge the request and provide the additional power to the PD; if the auxiliary PSE does not have excess power, it can deny the request.If the auxiliary PSE rejects the request, the PD may experience a power shortage and fail. The auxiliary PSE may also arbitrarily decide whether to accept or reject the request for additional power. This is because the auxiliary PSE does not know the power availability and PoE configuration of the main PSE. For example, the auxiliary PSE does not know for how long it should provide the additional power, whether the main PSE can still supply part of the additional power and the auxiliary PSE can supply the remaining power, the reliability of the main PSE, and so on. If the auxiliary grid operator arbitrarily decides to reject the request for additional power, the PD may fail due to a power shortage.For example, in the event of a maintenance event, allocating PoE to the PD by the auxiliary PSE without considering the power availability and PoE configuration of the main PSE may result in a power shortage, leading to power outages in the PD.

[0012] To address the above-mentioned issues, the examples disclosed herein provide, among other things, for the exchange of information between main and auxiliary PSEs related to their ability to deliver PoE power to a PD. Specifically, the PSEs dynamically exchange information about their current PoE configuration, including changes to such PoE configurations. This allows a PSE to intelligently adjust its own power allocations and / or other settings when something changes at the other PSE, such as a change in the other PSE's PoE configuration. This can ensure that the power allocated to the shared PD is not too high or too low, without requiring an administrator to monitor the PSEs for changes and manually reconfigure the PSEs.

[0013] More specifically, in some examples disclosed herein, two PSEs powering a PD may exchange a first set of transport-layer protocol communications to establish a power availability table based on the first set of communications. The power availability table refers to a tabular representation of information characterizing or representative of the PoE configurations of the two PSEs. Such information (also called PoE configuration information) may be programmed into each of the two PSEs during installation or later modified during operation. The PoE configuration information of the two PSEs and any changes thereto may be captured / updated in the power availability table.The PSEs can communicate with each other periodically or episodically to update the power availability table, including exchanging PoE configuration changes. In response to a change in the power availability table or to a change in the ability of one of the PSEs to power the PD, the PSE can send a second set of transport-layer protocol communications requesting the other PSE to adjust the other PSE's power allocation for the PD. In response to the second set of messages, the other PSE can change the power allocation for the PD as requested. In this way, the PSEs' power allocation for the PD can be dynamically adjusted, taking into account changes in the PoE configuration in the PSEs and the PSEs' ability to power the PD, thus ensuring uninterrupted power supply to the PD.

[0014] In one example, a PSE may exchange a first set of transport layer protocol communications with an additional PSE. The additional PSE and the PSE are connected to a PD to provide PoE to the PD. The first set of transport layer protocol communications includes a first communication from the PSE to the additional PSE that includes a first PoE configuration field containing first PoE configuration data indicating a PoE configuration of the PSE. The PoE configuration refers to the attributes, components, and parameters / settings of the PSE that relate to or affect the PSE's ability to provide PoE. For example, the PoE configuration of a PSE may include the PSE's PoE capabilities (e.g., the number and type of PSUs that are part of the PoE, a PoE power budget, etc.) and the connections and / or states and / or configuration of the PSE's PoE-capable ports.The PoE configuration may further include PoE-related settings of the PSE, which may be factory-preset or set by the administrator during PSE installation. The first set of transport layer protocol communications further includes a second communication from the additional PSE to the PSE, comprising a second PoE configuration field containing second PoE configuration data indicating a PoE configuration of the additional PSE. The PSE may create a power availability table for the PD based on information from the first PoE configuration field and the second PoE configuration field, the power availability table indicating the availability of PoE for the PD from the PSE and the additional PSE. The PSE may detect the occurrence of an event comprising at least one of a change in the power availability table and a change in the ability of the PSE to supply power to the PD.The event may relate to a change in PoE-related conditions / settings in one of the PSEs connected to the PD, which may impact power flow from one of the PSEs to the PD. Based at least in part on the occurrence of the event, the PSE may send a second set of transport-layer protocol communications to the additional PSE, wherein the second set of transport-layer protocol communications includes a request to the additional PSE to adjust a power allocation of the additional PSE for the PD.

[0015] By creating the power availability table from the PoE configurations of the PSE and the additional PSE and monitoring changes in this table, the PSE can decide whether an adjustment of the power allocation for the PD is necessary due to a change in the PoE configuration of the PSE or the additional PSE. Based on a change in the power availability table or a change in the PSE's ability to supply power to the PD, the PSE can send notifications to the additional PSE, requesting it to adjust its power allocation for the PD. By balancing the PoE power allocation between the PD and the additional PSE, the PSE can prevent outages in the PD due to power shortages at the PSE and enable efficient PoE allocation.By avoiding power shortages, an uninterrupted PoE supply to the PD can be maintained, and efficient PoE allocation can optimally utilize the PoE capabilities of the PSE and the additional PSE.

[0016] The above systems and methods are described with reference to Fig. until Fig.described in more detail. It should be noted that the description and drawings merely illustrate the principles of the present subject matter, together with the examples described herein, and should not be construed as limiting the present subject matter. It is therefore to be understood that various arrangements may be devised which, although not expressly described or shown herein, embody the principles of the present subject matter. Furthermore, all statements contained herein describing principles, aspects, and embodiments of the present subject matter, as well as specific examples thereof, are to be understood as including equivalents thereof.

[0017] The figures describe various devices, systems, and methods consistent with aspects of the present disclosure.

[0018] Fig.is a block diagram that conceptually represents two PSEs for use in a PoE system 100 in the form of PSE 105 and PSE 110. It should be understood that Fig. is not intended to depict specific shapes, dimensions, or other structural details accurately or to scale, and that implementations of the PSE 105 and PSE 110 may have different numbers and arrangements of the illustrated components and may also include other parts not shown.

[0019] As in Fig. As shown, the PSE 105 includes switching hardware 115, a power supply 120, a plurality of PoE ports 125 (“Ports 125”), and a control circuit 130.

[0020] The switching hardware 115 includes circuitry that can selectively connect the ports 125 to each other and to one or more other ports (not shown), such as an uplink port, to enable the forwarding of data packets between the various devices connected to the PSE 105, as well as other associated components that participate in, control, or otherwise facilitate the communication of the data packets.

[0021] The power supply 120 supplies electrical power to the PSE 105, including power for the functions of the PSE 105 itself and the PoE power to be delivered from the PSE 105 to the connected PDs via ports 125. The power supply 120 can be controlled by the control circuit 130 to selectively control the PoE power to the ports 125, or in other words, the power supply 120 can increase or decrease the PoE power to specific ports 125 at the instruction of the control circuit 130 as needed (e.g., during adjustment of the PSE's power allocation to the PD). The power supply 120 includes one or more power devices configured to receive input power from a power source, such as utility power, and convert that power into forms suitable for use by the PSE 105.In one example, the power supply 120 may consist of or be connected to one or more power supplies. The PSUs may be connected to the electrical grid. A power supply is a power source that supplies power to an electrical load. Examples of power supplies include uninterruptible power supplies (UPS) and power converters. The power supply 120 may also consist of or be connected to multiple power supplies. Depending on the total input power received by the power supply 120, the control circuitry 130 may instruct the power supply 120 to allocate the PoE power. The power devices of the power supply 120 may include an AC-to-DC converter, a DC-to-DC converter, protection devices (e.g., overcurrent protection, overvoltage protection, etc.), and / or other power components that participate in, control, or otherwise facilitate the power supply to the PSE 105.

[0022] Ports 125 include PoE-capable interfaces of the PSE 105, which may include, for example, RJ45 jacks. Each port 125 is configured to accept a connector of an Ethernet cable, which may include an RJ45 connector. Each port 125 is coupled to control circuitry 130 (e.g., via switching hardware 115) and configured to transmit data between control circuitry 130 and a PD connected to port 125. Each port 125 is also coupled to power supply 120 and configured to supply the PD connected to port 125 with PoE power from power supply 120. Fig.Three ports (i.e., ports 125_1, 125_2, 125_N) are shown, but any number of ports 125 equal to or greater than two may be included in the PSE 105. In some examples, ports 125 may provide interfaces for connecting Ethernet cables or other communications cables for communication with the PSE 110. The PSE 105 may communicate with the PSE 110 via ports 125 over a communications network, which may be a private network, such as a local area network (LAN) or wide area network (WAN), or a public network, such as the Internet.

[0023] Control circuitry 130 includes circuitry configured (e.g., programmed) to perform operations 135-155. Control circuitry 130 includes a processor and a storage medium storing instructions executable by the processor to cause operations 135-155 to be performed, or specialized hardware configured to perform operations 135-155, or a combination of these elements. In examples where control circuitry 130 includes a processor, the processor may include one or more processing devices capable of executing machine-readable instructions, such as a processor, a central processing unit (CPU), a controller, a microcontroller, a system-on-chip (SoC), a digital signal processor (DSP), a graphics processing unit (GPU), or other processing resources.In examples where control circuitry 130 includes dedicated hardware in addition to or instead of the processor, the dedicated hardware may include any electronic device configured to perform specific operations, such as an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), a complex-programmable logic device (CPLD), discrete logic circuits, a hardware accelerator, a hardware encoder, etc. In some examples, control circuitry 130 may be configured to control other operations of PSE 105 in addition to operations 135-155, such as controlling operations of switching hardware 115, operations of power supply 120, security / authentication operations, and / or other operations of PSE 105.

[0024] As in Fig.As shown, the additional PSE 110 includes the switching hardware 155, a power supply 160, a plurality of PoE ports 165 (“Ports 165”), and a control circuit 170.

[0025] The switching hardware 155, power supply 160, ports 165, and control circuitry 170 of the additional PSE 110 are similar to the switching hardware 115, a power supply 120, a plurality of PoE ports 125 (“Ports 125”), and control circuitry 130 of the PSE 105, respectively.

[0026] As in Fig.As shown, the PSE 105 and the additional PSE 110 are connected to the PD 174 via respective communication links 172-1 and 172-2, collectively referred to as communication links 172, to provide PoE and exchange communication with the PD 174. The PSE 105 and the additional PSE 110 are connected to each other via a communication link 173. The communication link 173 connects a PoE-capable port 125-2 of the PSE 105 to a PoE-capable port 165-2 of the additional PSE 110. The communication link 173 may extend over a communication network, which may be a private network, such as a local area network (LAN) or a wide area network (WAN), or a public network, such as the Internet.

[0027] The PD 174 may include a control circuit and one or more ports (not shown). The PD 174 may be any PoE-enabled electronic device, such as network devices (e.g., wireless access points), IP phones, IP security cameras, laptops, computer monitors, point-of-sale kiosks, sensors, other IoT devices, or other PoE-enabled electronic devices.

[0028] Operation 135, which control circuitry 130 is configured to perform, includes sending a first transport layer protocol communication from the PSE 105 to the additional PSE 110, including a first PoE configuration field containing first PoE configuration data indicative of a PoE configuration of the PSE 105. Operation 140, which control circuitry 130 is configured to perform, includes receiving a second transport layer protocol communication from the additional PSE 110 to the PSE 105, including a second PoE configuration field containing second PoE configuration data indicative of a PoE configuration of the additional PSE 110. The first transport layer protocol communication and the second transport layer protocol communication may collectively be referred to as a first set of transport layer protocol communications.Operations 135 and 140 enable PSE 105 to exchange the first set of transport layer protocol communications with additional PSE 110 (via ports 125). In some examples, the PoE configuration of the PSE 105 includes the PoE capabilities of the PSE 105, where the PoE capabilities of the PSE 105 include at least one of the following: a power budget of the PSE 105, a firmware version of the PSE 105, or a configuration of the PSUs of the PSE 105. In some examples, the PoE configuration of the PSE 105 includes a configuration of PoE-capable ports of the PSE 105, where the configuration of PoE-capable ports of the PSE 105 includes at least one of the following: a number of PoE-capable ports, respective power allocations of the PoE-capable ports, respective power consumption amounts of the PoE-capable ports, respective port priorities of the PoE-capable ports, or respective states of the PoE-capable ports.

[0029] A management IP (Internet Protocol) address of the additional PSE 110 can be programmed into the PSE 105, for example, by a network administrator manually entering the address or through an automatic discovery process that occurs in response to the communicative coupling of the PSE 105 and the additional PSE 110. The PSE 105 can be configured to send the first message to the management IP address of the additional PSE 110. The management IP address is a unique identifier assigned to a network device for its remote management. The management IP address provides a web interface that enables remote management tasks, troubleshooting a remotely managed system, and configuring the network device. Upon sending the first message, the PSE 105 can be configured to receive the second message from the management IP address of the additional PSE 110.The PSE 105 may extract information from the first PoE configuration field and the second PoE configuration field to create a power availability table, as explained later. In some examples, the additional PSE 110 may also create the power availability table from the first PoE configuration field and the second PoE configuration field and share a copy of it with the PSE 105. The decision regarding which PSE creates the power availability table depends on which PSE is selected as the primary PSE. There are several approaches to selecting the primary PSE, some of which are explained in more detail later in the description.

[0030] In some examples, the transport layer protocol is the Transmission Control Protocol (TCP) / Internet Protocol (IP), a collection of rules and procedures used to connect network devices on the Internet. In general, TCP / IP communication consists of an Ethernet frame, a communication structure that includes a series of data fields formatted and ordered according to the TCP / IP protocol specifications, such as a source port, a destination port, followed by a series of mandatory Type Length Values ​​(TLVs), followed (optionally) by optional TLVs. Preambles, end fields, and other encapsulation data may also be included.

[0031] TCP / IP communication generally consists of one or more TCP segments. A TCP segment generally consists of a header and a data portion. The data portion follows the header and is the payload transmitted for the application / process. The header contains the source port and the destination port. The source port identifies the process that sent the data (i.e., the payload in the TCP segment), and the destination port identifies the process that should receive the data. In the examples described here, the destination port can be a well-known port or a system port assigned by convention to a proprietary network process for communicating PoE-based configuration information between two PSEs. In one example, the proprietary network process for communicating PoE-based configuration information between two PSEs may be referred to as the Inter PSE Communications Protocol (IPCP).IPCP refers to a set of rules / procedures for the exchange and synchronization of PoE-related configuration information between two PSEs that supply PoE to a shared PD, as well as rules / procedures for PoE power balancing between the PSEs. Well-known ports, or system ports, can refer to port numbers defined by the Internet Assigned Numbers Authority (IANA) in the range 0 to 1023 (0 to 2). 10 - 1) used by system processes that provide various network services.

[0032] In some examples, the first communication from the PSE 105 to the additional PSE 110 includes a first TCP segment carrying a payload to be delivered to a destination port (which is an assigned well-known port / system port) for an IPCP application / process. The payload in the first TCP segment may include the first configuration field, which in one example may be encoded as a Type-Length-Value (TLV). In some examples, the second communication from the additional PSE 110 to the PSE 105 includes a second TCP segment carrying a payload to be delivered to the destination port (which is an assigned well-known port / system port) for the IPCP application / process. The payload in the second TCP segment may include the second configuration field, which in one example may be encoded as a Type-Length-Value (TLV). Please note that the first and second PoE configuration fields are configured using the same field (e.g.the same TLV), which may be generally referred to herein as a PoE configuration field. The terms "first" and "second" are used herein with respect to the PoE configuration fields to distinguish which PSE sent the communication in which the PoE configuration field is included, i.e., the first PoE configuration field refers to the PoE configuration field included in a communication from PSE 105, and the second PoE configuration field refers to the PoE configuration field included in a communication from PSE 110. In some examples, the payload in the first TCP segment (the first communication) from PSE 105 to additional PSE 110 includes a set of TLVs, such as the first PoE configuration field, line card information, authentication information, primary / auxiliary selection information, and packet type.The line card information includes line card numbers or port numbers for each PoE-capable port or line card in the PSE 105. The line card number or port number may be vendor-specific. The authentication information may include an integrity check value (ICV) or checksum to determine the integrity of the initial communication. The authentication information may be generated using security algorithms, hashing techniques, or secret keys. The packet type may indicate that the initial communication is a "Discovery Initiation" packet sent from the PSE 105 to the additional PSE 110. The "Discovery Initiation" packet may be an indication to the additional PSE 110 that the PSE 105 intends to exchange the first set of transport layer protocol communications containing PoE configuration information with the additional PSE 110.In response to receiving the "Discovery Initiation" packet, the additional PSE may check whether the additional PSE 110 is capable of exchanging transport layer protocol communications containing PoE configuration information with the PSE 105. The primary / auxiliary selection information indicates that either the PSE 105 or the additional PSE 110 has been selected as the primary PSE. If the PSE 105 is selected as the primary PSE, it is responsible for performing operations 145 through 155. The additional PSE 110 may be referred to as the auxiliary PSE. While the primary PSE performs operations 145 through 155, a copy of the data (e.g., the power availability table) generated and / or associated with these operations may be stored and regularly updated in the auxiliary PSE, which acts as a backup.

[0033] In response to receiving the first communication from the PSE 105, the additional PSE 110 may check the packet type to determine that the first communication is a “Discovery Initiation” packet. Upon receiving the “Discovery Initiation” packet, the additional PSE 110 may check whether the additional PSE 110 has the capability to send a transport layer protocol communication with the PoE configuration of the additional PSE 110 to the PSE 105. If the additional PSE 110 is determined to be capable of sending transport layer protocol communication with the PoE configuration, the additional PSE 110 may send the second communication to the PSE 105. In some examples, the second communication from the additional PSE 110 to the PSE 105 includes a source IP address followed by a series of TLVs, such as: E.g. the second PoE configuration field, line card information, authentication information, main / auxiliary selection information and packet type.The source IP address refers to a management IP address of the additional PSE 110 from which the second communication originates. The line card information includes line card numbers or port numbers of each PoE-capable port or line card in the additional PSE 110. The line card number or port number can be vendor-specific. The authentication information includes an integrity check value (ICV) or checksum to determine the integrity of the second communication. The authentication information can be generated using security algorithms, hashing techniques, or secret keys. The packet type can indicate that the second communication is a "discovery reply" sent from the additional PSE 110 to the PSE 105, indicating that the additional PSE 110 has the capability to share transport layer protocol communications with PoE configuration.The main / auxiliary selection information indicates that one of the PSE 105 or the auxiliary PSE 110 is selected as the main PSE for performing operations 140 through 150. Although in the example of . Fig. In other examples, if PSE 105 is selected as the main PSE and operations 145 through 155 are performed by PSE 105, additional PSE 110 may also be selected as the main PSE. Consequently, control circuitry 170 of additional PSE 110 may also be configured to perform operations identical to operations 135 through 155 performed by control circuitry 130 of PSE 105.

[0034] The operation 145 that the control circuit 130 is configured to perform includes creating a power availability table for the PD 174 based on information from the first PoE configuration field and the second PoE configuration field. The power availability table is an indicator of the availability of PoE for the PD 174 from the PSE 105 and the additional PSE 110. The power availability table may include information indicating the PoE configuration of the PSE 105 and the PoE configuration of the additional PSE 110.In one example, the power availability table may include a unique identifier for the PD 174 connected to the PSE 105 and the additional PSE 110, a port identifier and port priority of a PoE-capable port of the PSE 105 connected to the PD 174, a port identifier and port priority of a PoE-capable port of the additional PSE 110 connected to the PD 174, the power consumption of the PD 174, and a power class of the PD 174. In one example, the unique identifier of the PD 174 may be a private IP address of the PD 174 or a vendor-specific address defined for PoE operation of the PD 174. In one example, the PSE 105 may send a copy of the power availability table to the additional PSE 110 and periodically update the copy of the power availability table based on the first PoE configuration field and the second PoE configuration field.Thus, the additional PSE 110 can also maintain the copy of the power availability table. In some examples, the additional PSE 110 can also create the power availability table from the first PoE configuration field and the second PoE configuration field and share a copy of it with the PSE 105. The decision about which PSE creates the power availability table depends on which PSE is selected as the primary PSE.

[0035] The operation 150 for which the control circuit 130 is configured includes detecting the occurrence of an event that includes at least one change in the power availability table or a change in the ability of the PSE 105 to supply power to the PD 174. In some examples, the power availability table includes the configuration of the PoE-capable ports of the PSE 105 and the additional PSE 110. Thus, any change in the configuration of the PoE-capable ports of the PSE 105 or the additional PSE 110 may be reflected in the power availability table. When the PSE 105 detects such a change in the power availability table, it may determine that the event has occurred. For example, the PoE functionality of the PoE-capable port of the additional PSE 110 connected to the PD 174 is disabled or the port priority of the PoE-capable port of the additional PSE 110 connected to the PD 174 is changed.The PSE 105 can identify such changes related to the configuration of the PSEs' PoE-capable ports using the power availability table and detect the occurrence of the event. Conversely, in some examples, changes in the PSE 105's PoE capabilities (e.g., the PSE 105's power budget, a PSE 105 firmware version, or a PSE 105 PSU configuration) may not be reflected in the power availability table. Such changes in the PSE 105's PoE capabilities may result in a change in the PSE 105's ability to power the PD 174. The control circuitry 130 can identify such changes in the PSE 105's PoE capabilities and detect the occurrence of the event.The process 150 may include monitoring for changes in the PoE configuration of the PSE 105 or the additional PSE 110 (which may be communicated to the PSE 105 via additional communication means) and updating the power availability table (if applicable) in accordance with these changes in the PoE configuration. In one example, a decrease in the PoE port priority of a PoE-capable port of the PSE 105 connected to the PD 174 may result in a change in the power availability table. Similarly, a decrease in the PoE port priority of a PoE-capable port of the additional PSE 110 (the change may be communicated to the PSE 105 via additional communication means) may result in a change in the power availability table. The control circuit 130 may be configured to detect the occurrence of the event in response to such a change in the power availability table.In another example, a decrease in the PoE power allocation of the PSE 105 may result in a change in the ability of the PSE 105 to power the PD 174, or similarly, a decrease in the PoE power allocation of the additional PSE 110. The control circuit 130 may detect the occurrence of the event in response to such a decrease in the PoE power allocation of the PSE 105. Similarly, if the PoE power allocation at the additional PSE 110 decreases, the control circuit 170 may detect the occurrence of the event in response to such a decrease. In one example, the change in the ability of the PSE 105 to power the PD 174 includes a reduction in the PoE power availability at the PSE 105.In some examples, the reduction in PoE power availability may be due to a change in the power budget of the PSE 105 or a reduction in the portion of the PoE allocation for the PD 174 when multiple PDs are connected to the PSE 105. In another example, the change in the ability of the PSE 105 to power the PD 174 includes a reduction in the number of PSUs connected to the PSE 105 (or the number of connected PSUs that are operational). With a reduction in the number of power supplies connected to the PSE 105, the PSE 105 may detect that the total power delivered by the power supplies has decreased and may subsequently change its power budget. Changing the power budget by the PSE 105 may result in a reduction in the PSE 105's PoE power allocation to the PD 174, which may result in a change in the PSE 105's ability to power the PD 174.Such a change can be detected by the PSE 105 as an event. Thus, the event can relate to a change in PoE-related conditions / settings in the PSEs (such as the PSE 105 and the additional PSE 110) connected to a PD (such as the PD 174), which can affect the flow of power from one of the PSEs to the PD. In one example, the event can also relate to a failure in the PSE's power hardware, a firmware update, a (planned / unplanned) maintenance operation, or another PoE-related operation that can interrupt the flow of power between the PSE and the PD.

[0036] Additionally, control circuitry 130 is configured to check whether transport-layer protocol communications with keep-alive communications are being exchanged between PSE 105 and additional PSE 110. Keep-alive communications include a message sent from one device to another to verify that the connection between the two is working or to prevent the connection from being lost. In one example, the transport-layer protocol is TCP, and the keep-alive communications are IPCP keep-alive messages exchanged between the IPCP application instances running in PSE 105 and additional PSE 110. An IPCP keep-alive message consists of a "packet type" and a "timestamp." The packet type indicates that these are IPCP keep-alive messages, and the timestamp indicates the time at which an IPCP keep-alive message was transmitted.Based on the timestamp, a subsequent IPCP keepalive message can be sent or the keepalive communication can be timed out, as appropriate. The PSE105 and the additional PSE 110 can be configured to send IPCP keepalive messages based on a keepalive time, a keepalive interval, and a keepalive retry parameter. The keepalive time is the duration between two keepalive transmissions in the idle state (which can be determined from the timestamp). The keepalive interval is the duration between two consecutive keepalive retries if the acknowledgment of the previous keepalive transmission has not been received. The keepalive retry is the number of retransmissions that must be performed before declaring the remote party unreachable.For example, if the additional PSE 110 is performing scheduled maintenance, a firmware update, or a reboot, it may be unavailable or offline for a period of time and cannot send keep-alive communication to the PSE 105 during that time. After a predefined number of keep-alive retries by the PSE 105, the PSE 105 can determine that the additional PSE 110 is unavailable or offline, thus detecting the occurrence of an event. This allows the PSE 105 to detect the occurrence of an event when the additional PSE 110 is going for scheduled maintenance, a firmware update, or a reboot.

[0037] The operation 155 that the control circuit 130 is configured to perform includes sending a second set of transport layer protocol communications to the additional PSE 110 based at least in part on the occurrence of the event. The second set of transport layer protocol communications includes a request to the additional PSE 110 to adjust a power allocation of the additional PSE 110 for the PD 174. In one example, the second set of transport layer protocol communications includes a control communication to the additional PSE 110 indicating to the additional PSE 110 to increase the power allocation of the additional PSE 110 for the PD 174 in response to the decrease in the number of PSUs connected to the PSE 105.The control communication may refer to an instruction, command, or request from the PSE 105 to the additional PSE 110, or vice versa, to make changes to the power allocation for the PD 174. In another example, the second set of transport layer protocol communications includes a control communication to the additional PSE 110 indicating to the additional PSE 110 to increase the additional PSE 110's power allocation for the PD 174 in response to the decrease in PoE power availability at the PSE 105.

[0038] In some examples, the control circuitry 130 may be configured to check whether a port of the additional PSE 110 connected to the PD 174 has a high priority based on the second PoE configuration field received from the additional PSE 110. In response to determining that the port of the additional PSE 110 does not have a high priority, the control circuitry 130 may be configured to send a control communication to the additional PSE 110 requesting the additional PSE 110 to increase the port priority of the port. In response to determining that the connection of the additional PSE 110 has the high priority, the control circuit 130 may be configured to send another control communication to the additional PSE 110, wherein the another control communication indicates a request to the additional PSE 110 to increase the power allocation of the additional PSE 110 for the PD 174.

[0039] In another example, the control circuit 130 may be configured to send a first link-layer protocol communication to the PD 174 in response to detecting the event, wherein the first link-layer protocol communication indicates to the PD 174 that the PSE 105 is undergoing maintenance. The control circuit 130 may be configured to send a second link-layer protocol communication to the PD 174, wherein the second link-layer protocol communication indicates a request to the PD 174 to adjust at least one of the power request, the PD signature configuration, and the PD power class so that the operation of the PD 174 is uninterrupted.

[0040] In some examples, the link layer protocol is the Link Layer Discovery Protocol (LLDP). In general, LLDP communication consists of an Ethernet frame, a communication structure that includes a series of data fields formatted and ordered according to the LLDP protocol specifications, such as address fields (e.g., destination address, source address), followed by a series of mandatory TLVs (e.g., a chassis ID TLV, a port ID TLV, etc.), followed (optionally) by so-called optional TLVs. Preambles, tail fields, and other encapsulation data may also be included. Some optional TLVs may be defined according to an industry standard, such as IEEE Std 802.1 AB, while other optional TLVs may be so-called custom TLVs, which may be vendor-specific.In some examples, performance query, PD signature configuration, and PD performance class may be added as new optional TLVs to an LLDP frame (which can be either a standard-defined optional TLV or a vendor-specific custom TLV) of the second link-layer protocol communication. In other examples, the link-layer protocol may be Cisco Discovery Protocol (CDP), Foundry Discovery Protocol (FDP), Nortel Discovery Protocol (NDP), Link Layer Topology Discovery (LLTD), or other similar link-layer discovery protocols. Such other link-level discovery protocols also define communication data structures, such as the Ethernet frame described above, that include various data fields, such as the TLVs described above, although the formatting, naming, and other details of the data structures may vary from one protocol to another.Regardless of the protocol used, Power Ask, PD Signature Configuration, and PD Power Class can be included in the communication structure as a new field or as a proprietary TLV.

[0041] The power request refers to the average PoE power required by the PD to continue normal operation. This can be expressed in watts. The PD signature refers to an operating configuration of a PD that depends on the PD's load, class, modes, and performance characteristics. A single-signature PD can have the same detection signature, classification signature, and power maintenance signature (MPS) for both pairs of a four-pair Ethernet cable, while a dual-signature PD can have independent signatures for both pairs. The PD power class refers to a categorization of a PD based on the PD's required power levels. The PoE IEEE standards define different classes for PDs based on their required power levels.

[0042] In addition to the operations described above, in some examples, the control circuitry 130 of the PSE 105 may be configured to perform any of the operations described below with respect to methods 300, 400, 500, and / or 600 of the Fig. Certain aspects of PSE 105 are discussed in Fig. explained in more detail, which shows a PoE system in which the PSE 105 can be used. Fig. will follow the description of Fig. described.

[0043] In Fig. A PD for use in a PoE system in the form of the PD 200 is described. Fig. is a block diagram that conceptually represents the PD 200. It should be understood that Fig.is not intended to depict specific shapes, dimensions, or other structural details accurately or to scale, and that implementations of the PD 200 may have a different number and arrangement of the components depicted and may also include other parts not shown.

[0044] As in Fig.As shown, the PD 200 includes a control circuit 220, a first uplink port 240-1, and a second uplink port 240-2, collectively referred to as uplink ports 240 (ports 240). An uplink port refers to an Ethernet port used as an interface for connecting a device to other network devices in a computer network, such as a local area network or a data center network. For example, a wireless access point in the access layer of a network can be connected to a network switch in the distribution layer via an Ethernet cable connected to the uplink port of the wireless access point. The PD 200 can be any PoE-enabled electronic device, such as network devices (e.g.,wireless access points), IP phones, IP security cameras, laptops, computer monitors, point-of-sale kiosks, sensors, other IoT devices, or other PoE-enabled electronic devices.

[0045] The ports 240 include PoE-capable connectors, which may include RJ45 jacks. Each port 240 is configured to accept a connector of an Ethernet cable, which may include an RJ45 connector. This allows the PD 200 to be connected to a PSE, such as the PSE 105 and the Fig. described additional PSE 110. Ports 240 are configured to receive PoE power and supply power to the other components of the PD 200. Ports 240 are also communicatively coupled to control circuitry 210 to transfer data between control circuitry 220 and another device (e.g., a PSE) connected to port 240. Fig.Two 240 ports are shown, but the PD 200 can contain any number of 240 ports, equal to or greater than one. Some PDs 200 have only one 240 port. Others can have two 240 ports so that the PD can be connected to multiple network devices (e.g., multiple PSEs) for redundancy. The PD 200 could also have more than two 240 ports.

[0046] The control circuit 220 includes circuitry configured (e.g., programmed) to perform the operations 222 through 230. The control circuit 220 includes a processor and a storage medium storing instructions executable by the processor to cause the operations 222 through 230 to be performed, dedicated hardware configured to perform the operations 222 through 230, or a combination thereof. In this context, the processor and dedicated hardware may include any of the examples discussed above with respect to the control circuit 130 of Fig.discussed. In some examples, control circuitry 220 may be configured to control other operations of PD 200 in addition to operations 222-230, such as operations that control communication of PD 200 with the PSE (which may be common to all PD types 200), as well as other operations that may be more specific to the functions of different PD types 200. Because PDs 200 may be a variety of devices with widely varying functions, the other operations performed by control circuitry 220 may vary from device to device. These other operations of PDs are known to those skilled in the art and are not described here.

[0047] Operation 222 includes receiving power from a first PSE via an Ethernet cable plugged into the first uplink port 240-1. In one example, the first PSE may be the PSE 105 of Fig.The Ethernet cable can be plugged into an RJ45 connector on the first uplink port 240-1. The PD 200 can be powered from the first PSE via Ethernet. When a PD connects to a PSE, such as the PSE 105 from Fig. , the PSE and PD can exchange information to dynamically determine the PSE's power allocation for the PD. The PD can present a PD power class signature to the PSE. The PD power class refers to a categorization of a PD based on the PD's required power levels. Each PD power class signature corresponds to a maximum power delivered by the PoE port and a power range of the PD. The PSE responds with a power allocation based on the PD's PD power class. This allows the PD 200 to receive PoE from the first PSE through its first uplink port 240-1.

[0048] Operation 224 includes receiving power from a second PSE via an Ethernet cable plugged into the second uplink port 240-2. In one example, the second PSE may be the additional PSE 110 of Fig. and the Ethernet cable can be plugged into an RJ45 connector on the second uplink port 240-2. This allows the PD 200 to receive power over Ethernet from the second PSE.

[0049] In one example, the first PSE and the second PSE connected to ports 240 of the PD 200 may maintain a power availability table indicating the availability of PoE for the PD 200. The power availability table may be created based on the PoE configuration of the first PSE and the PoE configuration of the second PSE. The first PSE may monitor the power availability for changes. Additionally, in some scenarios, the first PSE may undergo scheduled maintenance, a firmware upgrade, or a reboot, which may result in a change in the first PSE's ability to deliver PoE to the PD 200. The first PSE may detect the occurrence of an event in response to a change in the power availability table or a change in the ability to deliver PoE to the PD 200. In response to detecting the event, the first PSE may send a first link-layer protocol communication to the PD 200.Operation 226 includes receiving the first link-layer protocol communication from the first PSE in response to the occurrence of the event, which includes at least one of a change in a power availability table of the PD 200 or a change in the ability of the first PSE to provide power to the PD 200. In one example, the PD 200 may receive the first link-layer protocol communication from the first PSE. The first link-layer protocol communication is an indication of a request to adjust PD power consumption. PD power consumption refers to the power consumption of the PD 200 to maintain normal operation of the PD 200. In some examples, the first link-layer protocol communication may be an LLDP frame with TLVs.The PD power consumption can be added to the LLDP frame as a new optional TLV (which can be either a standard-defined optional TLV or a manufacturer-specific custom TLV), indicating that the PD power consumption needs to be adjusted, i.e., can be either decreased or increased. In other examples, the PD power consumption TLV can also indicate that the PD power consumption needs to be adjusted such that the power consumption of the PD 200 from the first PSE is reduced by a certain amount and a corresponding amount of additional power is purchased from the second PSE. Thus, if the first power grid operator is unable to meet the power demand of the PD 200, the PD 200 can request the second power grid operator to purchase the additional power from the second power grid operator, thus maintaining its operation without interruptions.

[0050] Operation 228 includes adjusting the PD power consumption based on the first link-layer protocol communication. In one example, if the PD Power Consumption TLV in the first link-layer protocol communication indicates that the PD 200 should reduce the power consumed by the first PSE by a certain amount and increase the power consumed by the second PSE by a corresponding amount, the control circuit 220 may make corresponding changes. In another example, the control circuit 220 is configured to transition the PD from a normal mode to a power-save mode in response to receiving the first link-layer protocol communication. The PD's normal mode corresponds to a higher power consumption mode of the PD 200 compared to the power consumption of the PD 200 in the power-save mode.Therefore, in power saving mode, the total power consumption of the PD 200 can be reduced, which can lead to a reduction in the total power consumption of the PD and thus also to a reduction in the power drawn from the first PSE.

[0051] Operation 230 includes sending a second link-layer protocol communication to the second PSE to purchase power from the second PSE based on the adjusted PD power consumption. In particular, the PD 200 may intend to purchase additional power from the second PSE based on the adjusted power consumption. In one example, the link-layer protocol is LLDP. Therefore, the second link-layer protocol communication includes an LLDP frame, which may include a TLV informing the second PSE of the PD's intent to purchase additional power from the second PSE. The TLV may include an adjusted power request from the PD 200 to the second PSE. The second PSE may monitor for LLDP communication from the PD 200.In response to receiving the second link layer protocol communication, the second PSE may allocate the additional power to the PD 200 according to the adjusted power demand, thereby meeting the power demand of the PD 200 and maintaining the uninterrupted operation of the PD 200.

[0052] Fig. shows a swim lane diagram of a method 300 for managing PoE delivered by two PSEs to a PD, according to an example. The method 300 includes operations 308 through 354 performed by a PSE 302, an additional PSE 304, and a PD 306, wherein the PD 306 is connected to the PSE 302 and the additional PSE 304 to receive PoE. The PSE 302 may perform similar functions as the PSE 105 of Fig. The additional PSE 304 can perform similar functions as the additional PSE 110 from Fig. and the PD 306 can perform similar functions as the PD 174 from Fig.or the PD 200 from Fig. Some aspects of the PSE 105, the additional PSE 110 and the PD 200 described above are described in Fig. not shown. In addition, descriptions of certain Fig. aspects already discussed above in relation to the Fig. described will be omitted below.

[0053] It is understood that the PD 306 may communicate with the PSE 302 and the additional PSE 304 via corresponding Ethernet cables plugged into the corresponding ports of the PSE 302 and the additional PSE 304. The PD 306, when connected to a PoE-enabled port of the PSE 302, may send a class signature to the PSE 302 at block 308. The class signature may define a required power level for the PD 306. At block 310, the PSE 302 responds with a power allocation based on the class signature of the PD 306. In one example, the PSE 302 may send an LLDP communication to the PD 306 with a maximum power delivered by the PoE-enabled port of the PSE 302. The maximum delivered power corresponds to the class signature of the PD 306.

[0054] During operation, at block 312, the PSE 302 may send a first communication 313 to the additional PSE 304. The first communication 313 may be a transport layer protocol communication. In particular, the first communication 313 may be a TCP / IP communication from the PSE 302 to the additional PSE 304, transmitting a payload to a destination port assigned to an IPCP application instance running on the additional PSE 304. The first communication may be sent to determine whether the PSE 302 and the additional PSE 304 are capable of sharing TCP / IP communication for exchanging PoE configuration information over IPCP. In one example, the PSE 302 may send the first message 313 to the additional PSE 304 over a PoE peer connection.A PoE peer connection refers to a point-to-point connection between an application instance running IPCP on the PSE 302 and an application instance running IPCP on the additional PSE 304 to exchange PoE configurations, where the point-to-point connection is established over TCP. Once the point-to-point connection is established between the PSE 302 and the additional PSE 304 to share PoE configurations, the PSE 302 and the additional PSE 304 can be referred to as IPCP peers with respect to each other. Thus, two PSEs can be referred to as "IPCP peers" if they can exchange transport-layer messages to synchronize PoE-related configurations between them. As shown in [context unclear]. Fig.As shown, the first communication 313 includes an Ethernet frame with a source address 313-a, PoE capabilities TLV 313-b, line card information TLV 313-c, authentication information TLV 313-d, main select TLV 313-e, and packet type TLV 311-f. The source address 313-a refers to an IP address of the PSE 302 from which the first communication originates. The PoE capabilities TLV 313-b refers to the PoE-related configuration of the PSE 302. The PoE capabilities TLV 313-b includes at least one of the following: a "power budget" of the PSE 302, "firmware information" of the PSE 302, or a configuration of the PSE 302's PSUs. An example of the PoE capabilities TLV 313-b is shown below: "PSU CONFIGURATION PSU: SLOT :1 POWER : 900W STATUS : Online PSU: SLOT 2: Power: 900 W STATUS : Online Redundant power supply: Enabled. FIRMWARE INFORMATION

[0055] Firmware<name> <version><Maximale Leistung> <klasse> POWER BUDGET: Available power: 900 W Card power: 600 W PoE power: 300 W POE mode: BT POE power used: 270 W Unused POE power: 30 W

[0056] In the PoE capabilities TLV 313-b example, the PSE 302 power supply configuration is represented by "PSU CONFIGURATION." The example shows that two power supplies are connected to the PSE 302, at "SLOT1" and "SLOT2," each capable of delivering 900 watts (W) of AC power, and are currently "online," meaning in operation. The "Power Budget" is an example of a PSE 302 power budget that can be included in the PoE capabilities TLV 313-b. In the above example, the "Power Budget" indicates that the total supply power is 900 W. The "Board Power" refers to the power reserved for operating the device itself, in this case, the PSE 302. Therefore, the PoE power that can be allocated is referred to as "PoE Power," which is (900 - 600) = 300 W. The power consumed by the PSE 302 is referred to as the non-PoE power consumed by the PSE 302.The total amount of PoE power consumed by the PDs connected to the PSE 302 is referred to as "Consumed PoE Power," which in this example is 270 watts. The "Unused PoE Power" is therefore (300 - 270) = 30 W. The "Firmware Info" contains information about the firmware name, version, maximum power the PoE controller can handle, and the classification of the PD 306 connected to the PSE 302.

[0057] The line card information TLV 313-c refers to a TLV that specifies the line card numbers or port numbers of the PoE-capable ports of the PSE 302 and the total number of these ports. The authentication information TLV 313-d refers to data protection rules used for encryption of the initial communication. The main selection TLV 313-e contains information that specifies which of the PSE 302 and the auxiliary PSE 304 is selected as the main PSE. The selection of the main PSE and the auxiliary PSE can be performed manually by an administrator or through a voting mechanism. With manual selection, the administrator can designate the PSE as the main PSE when configuring a PSE. The PSE designated as the main PSE can send the main selection TLV 313-e with a specific value that indicates that the sender is the main PSE.As part of the election mechanism, a PSE can check its PSU configuration (whether it has multiple PSUs online and healthy), the available PoE power, whether maintenance / firmware upgrade is scheduled, etc., to claim to be the primary PSE. If multiple redundant power supplies are connected to the PSE, the available PoE power is sufficient, and no maintenance / firmware upgrade is scheduled, the PSE can claim to be the primary PSE and send the Principal Select TLV 313-e indicating this. For example, if a larger number of PSUs are connected to PSE 302 than to the auxiliary PSE 304, and the remaining PoE power in PSE 302 is above a threshold, PSE 302 can send the Principal Select TLV 313-e indicating that PSE 302 is the primary PSE. The TLV 313-f packet type indicates that the first communication is a Discovery Initiation packet.A "Discovery Initiation" packet indicates to the intended receiver (in this case, the additional PSE 304) that the source (i.e., the PSE 302) intends to exchange transport layer protocol communications to share PoE configurations with the receiver and inquires whether the receiver has capabilities to perform this exchange.

[0058] In some examples, in response to receiving the first communication, the additional PSE may first send a discovery acknowledgement packet (Disc ACK) back to the PSE 302 (in Fig. not shown). The "Disc ACK" may be an acknowledgment message from the additional PSE 304 to the PSE 302 that the additional PSE 304 has received the "Discovery Initiation" packet. Further, the additional PSE 304 may analyze the first communication. In one example, analyzing the first communication may include the additional PSE 304 checking the packet type TLV 313-f to determine that the first communication is a "Discovery Initiation" packet, and then a control circuit of the additional PSE 304 may detect the PoE configuration of the additional PSE 304 to respond to the first communication. In block 314, the additional PSE 304 may check whether the additional PSE 304 has the capability to exchange transport layer protocol communications with the PSE 302 to exchange PoE configurations. In particular, the additional PSE 304 can check whether an application instance of IPCP is running in the additional PSE 304.Further, during the analysis, the additional PSE 304 may also examine the main selection TLV 313-e in the first communication to determine which of the PSE 302 and the additional PSE 304 should act as the main PSE and / or the auxiliary PSE. In this example, based on the main selection TLV 313-e, the additional PSE 304 may determine that the PSE 302 is the main PSE and the additional PSE 304 is the auxiliary PSE. In response to determining that the additional PSE 304 is capable of exchanging transport layer protocol communication with the PSE 302, the additional PSE 304 may send a second communication 315 to the PSE 302 at block 316. The second communication 315 may be a transport layer protocol communication.In particular, the second communication 315 may be a TCP / IP communication from the additional PSE 304 to the PSE 302 carrying a payload to be delivered to a destination port assigned to an IPCP application instance running in the PSE 302. The second communication may be sent to indicate to the PSE 302 that the additional PSE 304 has the capability to utilize TCP / IP communication for exchanging PoE configuration information using IPCP.The second message 315 includes a source address field 315-a with an IP address of the additional PSE 304, a PoE capabilities TLV 315-b with a PoE configuration of the additional PSE 304, line card information 315-c with line card numbers of PoE-capable line cards and a total number of PoE-capable line cards in the additional PSE 304, authentication information TLV 315-d comprising data protection rules used for encoding the second communication, a primary selection TLV 315-e containing information indicating which of the PSE 302 and the additional PSE 304 was selected as the primary PSE, and a packet type TLV 315-f indicating that the second communication is a "discovery response." The Discovery Reply packet may indicate that the additional PSE 304 is connected to PSE 302 to exchange IPCP data packets over TCP.Once the "Discovery Reply" packet is received by the PSE 302, a point-to-point connection for exchanging IPCP messages can be established between the PSE 302 and the additional PSE 304. Thus, upon receipt of the "Discovery Reply" packet, the PSE 302 and the additional PSE 304 can be established as an "IPCP peer" with respect to each other. After the PSE 302 receives the "Discovery Reply," the PSE 302 and the additional PSE 304 can be understood as "IPCP peer established." The "IPCP peer established" state refers to an operational state of a PSE in which the PSE can communicate with its "IPCP peer" over a point-to-point network connection. Although in the example of . Fig. In other examples, if the PSE 302 is selected as the main PSE, the additional PSE 304 may also be selected as the main PSE. Consequently, the control circuitry of the additional PSE 304 may also be configured to perform operations identical to those performed by the control circuitry of the PSE 302.

[0059] In one example, in response to receiving the second message from the additional PSE 304, the PSE 302 may determine from the primary selection TLV 315-e that the PSE 302 has been selected as the primary PSE. Therefore, upon receiving the second message, the PSE 302 may announce that the PSE 302 is the primary PSE at block 318. Once the PSE 302 has been announced as the primary PSE, the additional PSE 304 may send a configuration of the PoE-capable ports of the additional PSE 304 to the PSE 302 at block 320. In one example, the additional PSE 304 may send the configuration of the PoE-capable ports of the additional PSE 304 to the PSE 302 via a transport layer protocol communication similar to the second communication. The transport layer protocol communication includes an Ethernet frame, also referred to as a remote announcement packet, such as the remote announcement packet 321.The remote announcement packet may refer to a TCP / IP packet for sharing the configuration of the PoE-enabled port of one PSE with another. The remote announcement packet 321 may be similar to the second communication and includes a source address 321-a, a PoE port configuration TLV 321-b, an authentication information TLV 321-c, a principal select TLV 321-d, and a packet type TLV 321-e. The authentication information TLV 319-c and the principal select TLV 319-d may be identical to the authentication information TLV 315-d and the principal select TLV 315-e of the second communication 315. The packet type TLV 321-e indicates that this Ethernet frame is a TCP / IP communication that includes the configuration of the PoE-enabled ports of the additional PSE 304. An example of the PoE port configuration TLV 321-b is [port -ge-0 / 0 / 0, PD identifier=floor5-1, port priority=high, Power consumed = 11.5 W, Power Class: Class A]."ge-0 / 0 / 0" refers to a port address of a PoE-capable port of the additional PSE 304, "floor5-1" refers to a unique identifier of the additional PSE 304, and "high" refers to the port priority of the "ge-0 / 0 / 0" port. In one example, the PoE port priority for an interface can be specified as "critical," "high," or "low," indicating a preference order or rank of the interface in the event of power oversubscription. Oversubscription in a PSE can refer to a phenomenon where more PDs are connected to the PSE than the PSE's power budget allows. Therefore, if the total power required by the PDs connected to a PSE is higher than the total PoE power available at the PSE, power oversubscription can result. For example, in the event of oversubscription, higher-priority ports take precedence over lower-priority ports.Therefore, in the event of oversubscription, higher-priority PoE-capable ports will receive PoE power, while lower-priority ports may not receive PoE power. "Power consumed" refers to the PoE power consumed by the PD connected to the "ge-0 / 0 / 0" port, and "power class" refers to a category of the PD connected to the PSE, indicating a maximum power requirement of the PD. The TLV 321-e packet type can identify the packet as a "remote announce" packet that shares the configuration of the PoE-capable ports of the additional PSE 304 with the PSE 302. Although the configuration of a single PoE-capable port "ge-01010" of the additional PSE 304 is shown above, the TLV 321-b PoE port configuration can include the configuration of other PoE-capable ports of the additional PSE 304.

[0060] In response to receiving the configuration of the PoE-capable ports of the additional PSE 304, the PSE 302 may advertise the configuration of the PoE-capable ports of the PSE 302 in block 322. In one example, the PSE 302 may publish the configuration of the PoE-capable ports of the PSE 302 in an Ethernet frame, also referred to as a local advertisement packet, such as local advertisement packet 323. In one example, the control circuitry of the PSE 302 may collect the configuration of all PoE-capable ports of the PSE 302 to create local advertisement packet 323. The local advertisement packet 323 includes a source address 323-a, a PoE port configuration TLV 323-b, an authentication information TLV 323-c, a main selection TLV 323-d, and a packet type TLV 323-e.The authentication information TLV 323-c and the main selection TLV 323-d may be similar to the authentication information TLV 313-d and the main selection TLV 313-e of the first communication 313. The packet type TLV 323-e indicates that this Ethernet frame contains the configuration of PoE-capable ports of the PSE 302. The packet type TLV 323-e may identify the packet as a "local announce" packet, via which the configuration of the PoE-capable ports of the PSE 302 is published locally within the PSE 302. Although in the example of . Fig. the operations of blocks 312 and 322 are shown separately, in one example, the operations of blocks 312 and 322 may be performed together, and the local announcement packet may form part of the detection initiation packet. Although in the example of Fig. the operations of blocks 316 and 320 are illustrated as separate, in one example, the operations of blocks 316 and 320 may be performed jointly, and the remote advertisement packet may form part of the detection initiation packet.

[0061] In response to receiving the configuration of the PoE-capable ports of the additional PSE 304 from the remote advertisement packet and the configuration of the PoE-capable ports of the PSE 302 from the local advertisement packet, the PSE 302 may create a power availability table in block 324. The power availability table contains PoE availability information for the PD 306 based on the configuration of the PoE-capable ports of the PSE 302 and the additional PSE 304. In block 326, the PSE 302 may send a copy of the power availability table to the additional PSE 304. An example of a power availability table 327 is shown in Fig. The power availability table 327 includes a PD identifier 327-a, a PSE primary port identifier and priority 327-b, a PSE secondary port identifier and priority 327-c, a consumed power 327-d, and a power class 327-e. The PSE 302 can create the power availability table 327 based on the PoE port configurations in the local advertisement packets 323 and the remote advertisement packets 321. An example of the creation of the power availability table 327 is shown below.

[0062] Note that the PoE port configuration is TLV 321-b in the Remote Announcement packet 321: {port -ge-0 / 0 / 0, PD identifier=floor5-1, port priority=high, Power consumed = 11.5 W, Power Class = 3}; {port -ge-01017, PD identifier=floor5-2, port priority=high, Power consumed = 11.5 W, Power Class = 3}

[0063] It should also be noted that the PoE port configuration TLV 323-b in the local announce packet is 323: {port -ge-0 / 0 / 6, PD identifier=floor5-1, port priority=high, Power consumed = 11.5 W, Power Class = 3}; { port -ge-0 / 0 / 3 , PD identifier=floor5-2 , port priority=high , Power consumed = 11.5 W , Power Class = 3} { port -ge-0 / 0 / 1 , PD identifier=floor5-5 , port priority=high , Power consumed = 9 W , Power Class = 2}

[0064] Based on the above PoE port configuration TLV 321-b and PoE port configuration 323-b, the PSE 302 can determine that the PDs with PD identifiers "floor5-1" and "floor5-2" are connected to both the PSE 302 and the additional PSE 304. Accordingly, the PSE 302 creates the following power availability table for the PDs "floor5-1" and "floor5-2." Energy availability table: PD identifier PSE main connection ID and priority PSE auxiliary port ID and priority Power consumed Performance class Floor 5-1 ge-0 / 0 / 0 "High" ge-0 / 0 / 6 "High" 11.5 3 Floor 5-2 ge-0 / 0 / 7 "High" ge-0 / 0 / 3 "High" 11.5 3 Thus, the power availability table can be created for the two PDs "Floor5-1" and "Floor5-2," each connected to both the PSE 302 and the additional PSE 304. The additional PSE 304 can save the copy of the power availability table after receiving it from the PSE 302.

[0065] The PSE 302 may regularly update the local announcement package and regularly receive updates of the remote announcement communication from the additional PSE 304. Based on these updates, the PSE 302 may update the power availability table 325. The PSE 302 may compare the power availability table 325 with its updated version to determine any changes in the power availability table. Thus, in block 328, the PSE 302 may check whether there is a change in the power availability table. In response to determining that there is a change in the power availability table, the PSE 302 may detect that an event has occurred. Although in Fig. Not shown, in response to the occurrence of the event, the PSE 302 may send an "Event Notification" to the additional PSE 304. The "Event Notification" packet may refer to a message sent from one PSE to another PSE using IPCP over TCP, where the "Event Notification" packet contains details related to the event. In one example, the event message may be sent from the PSE 302 to the additional PSE 304 using IPCP over TCP. The "Event Notification" packet may contain a collection of TLVs. An example "Event Notification" packet is shown below. Source Address PoE event Author info Mainly choose Package type

[0066] In the example "Event Notification" packet, the "Source Address" field can be similar to Source Address 313-a or Source Address 323-c, as previously described. The "Auth Info" field can be similar to Auth Info 313-d or Auth Info 323-c, as previously described. Likewise, the "Principal Select" field can be similar to Principal Select 313-e or Principal Select 323-d, as previously described. The "PoE Event" TLV can provide an indication of the type of event that occurred. For example, the "PoE Event" TLV can indicate that the event is a "firmware update," a "port configuration change," a "PSU configuration change," "scheduled maintenance," a "reboot," etc. The "Packet Type" TLV can indicate that this particular packet is an "event notification" packet.

[0067] Further, in response to detecting a change in the power availability table ("Yes" branch of block 328), the PSE 302 may analyze the power availability table to determine the change. In some examples, the port priority of a PoE-capable port of the PSE 302 connected to the PD 306 may be decreased, e.g., from "high" to "low." In other examples, the port priority of a PoE-capable port of the PSE 302 connected to the PD 306 may be increased, e.g., from "low" to "high." The PSE 302 may detect these changes in port priority based on the power availability table. For purposes of this discussion, it is assumed that the port priority of the PoE-capable port of the PSE 302 is decreased.In block 330, the PSE 302 determines that the change in the power availability table corresponds to a decrease in the port priority of a PoE-capable port of the PSE 302 connected to the PD 306. In one example, the port priority of the PoE-capable port of the PSE 302 may be changed from "high" to "low." Next, in block 332, the PSE 302 may check whether a PoE-capable port of the additional PSE 304 connected to the PD 306 has a "high" priority. In response to determining that the PoE-capable port of the additional PSE 304 connected to the PD 306 has a "high" priority (branch "yes" from block 332), the PSE 302 may send a control communication to the additional PSE 304 in block 334.In one example, the control communication is a transport-layer protocol communication that represents a request to the additional PSE 304 to increase the additional PSE 304's power allocation for the PD 306. In response to determining that the port of the additional PSE 304 does not have high priority ("No" branch of block 332), the PSE 302 may send a control message to the additional PSE 304 in block 336 requesting the additional PSE to increase the port priority of the port connected to the PD 306.

[0068] In response to determining that there is no change in the power availability table ("No" branch of block 328), the PSE 302 may check in block 338 whether the number of power supplies connected to the PSE 302 has changed. In one example, the PSE 302 may compare the first message, such as the first message 313, with a subsequent first message, which may be an update to the first message 313, to identify the change. The PSE 302 may compare one version of the PoE Capabilities TLV 313-b with another version of the PoE Capabilities field generated after a predefined time. Depending on this comparison, the PSE 302 may detect changes in the number of PSUs or the PSU configuration.In one example, a change in the number of power supplies or power supply configuration may be one of multiple power supplies connected to the PSE 302 being disconnected or a power supply going offline, or a change in the power redundancy configuration. Similarly, the PSE 302 may also determine if there is a change in the power budget of the PSE 302 by reviewing the first communication 313 in block 338. In one example, a change in the power budget may include an increase in the reserved base power, an increase in non-PoE power consumption, or a decrease in the total power allocated for PoE. A change in the PSU configuration or a change in the power budget may indicate a change in the ability of the PSE 302 to deliver PoE to the PD 306.In some examples, in response to detecting a change in the number of PSUs or the power budget of the PSE 302, the PSE 302 may send an "Event Notification" packet to the additional PSE 304. The "Event Notification" packet may be similar to the "Event Notification" packet described previously.

[0069] Further, in response to detecting a change in the number of PSUs or the power budget of the PSE 302 ("Yes" branch of block 338) at block 334, the PSE 302 may send a control communication to the additional PSE 304. In one example, the control communication is a transport layer protocol communication over IPCP requesting the additional PSE 304 to increase the additional PSE 304's power allocation for the PD 306. In response to receiving the control message, the additional PSE may satisfy the request and increase the additional PSE 304's power allocation for the PD 306 at block 340. Thus, based on a change in the power availability table or a change in the PSE's ability to power the PD, the PSE may send messages to the additional PSE requesting it to adjust its power allocation for the PD.The additional PSE 304, now aware of the PoE availability for the PD on the PSE 302, can then adjust the PoE power allocation for the PD, thus preventing PD outages due to power shortages. This enables efficient allocation of PoE to the PD by the PSE and the additional PSE.

[0070] In response to determining that there is no change in the power availability table (“No” branch of block 328) and no change in the number of PSUs, the PSU configuration, or the power budget of the PSE 302 (“No” branch of block 338), the PSE 302 may check in block 344 whether keep-alive communications are being received from the additional PSE 304. Although the operations in blocks 328, 338, and 344 in the example of Fig. are executed sequentially, in another example, the operations in blocks 328, 338, and 344 may be executed in parallel by the PSE 302. In one example, the keep-alive communications are PCP keep-alive messages.

[0071] In one example, the PSE 302 may have a scheduled maintenance activity, such as a firmware upgrade, during which the PSE 302 continues to exchange keep-alive communication with the additional PSE 304. The PSE 302 may send an "Event Notification" to the additional PSE 304 indicating that the PSE 302 has scheduled the firmware upgrade. As previously mentioned, the "Event Notification" is sent from the PSE 302 to the additional PSE 304 using IPCP over TCP. The "Event Notification" may include a "PoE Event" TLV indicating an impending firmware upgrade for the PSE 302. Upon receiving this "event notification" from the PSE 302, the additional PSE 304 can instruct the PD 306 (via link layer communication) to draw more power from the additional PSE 304 and consequently provide more power to the PD 306.The PD 306 may confirm to the additional PSE 304 that it will now draw more power from the additional PSE 304. The additional PSE 304 may then send an acknowledgment to the PSE 302, indicating to the PSE 302 that it should perform the firmware upgrade. In one example, the PSE 302 may put the scheduled maintenance operation on hold until the acknowledgment is received from the additional PSE 304. Upon receiving the acknowledgment from the additional PSE 304, the PSE 302 may perform the scheduled maintenance. Upon completion of the scheduled maintenance, the PSE 302 and the additional PSE 304 may return to their respective "IPCP Peer Established" states.

[0072] In another example, the PSE 302 may be "rebooted" or a PoE port of the PSE 302 connected to the PD may be shut down, in which case the PSE 302 may be unable to exchange keep-alive communications with the additional PSE 304. The PSE 302 may send an "event notification" to the additional PSE 304 indicating that the PSE 302 will not be able to exchange keep-alive communications after a certain period of time. The "event notification" may include a "PoE Event" TLV indicating an impending reboot or shutdown of the PoE port of the PSE 302. Upon receiving this "event notification" from the PSE 302, the additional PSE 304 can instruct the PD 306 (via link layer communication) to draw more power from the additional PSE 304 and, consequently, to provide more power to the PD 306.The PD 306 may confirm to the additional PSE 304 that it will now draw more power from the additional PSE 304. The additional PSE 304 may then send an acknowledgment to the PSE 302, instructing the PSE 302 to perform the port restart / shutdown. In one example, the PSE 302 may defer the port restart / shutdown operation until the acknowledgment is received from the additional PSE 304. Upon receiving the acknowledgment from the additional PSE 304, the PSE 302 may perform the port restart / shutdown. Once the PSE 302 performs a port restart / shutdown, the keep-alive communication between the PSE and the additional PSE 304 may be terminated. After the PSE 302 is restarted / the connection is put back into operation, the PSE 302 and the additional PSE 304 can initiate detection again, for example in block 312.

[0073] In some examples, after a predefined number of keepalive retries by the PSE 302, the PSE 302 may determine that the additional PSE 304 is unable to exchange transport layer protocol communications with the PSE 302 if no keepalive communication is received from the additional PSE 304 ("No" branch of block 344). Therefore, in block 346, the PSE 302 may send a first link layer protocol communication to the PD 306 indicating that the additional PSE 304 is performing maintenance, a firmware update, or a reboot of the additional PSE 304. In response to receiving a keep-alive communication from the additional PSE 304 within the predefined keep-alive retries ("Yes" branch from block 344), the PSE 302 may further monitor the keep-alive communication and the power availability table in block 348.

[0074] After sending the first link-layer protocol communication to the PD 306, the PSE 302 may send a second link-layer protocol communication to the PD 306 to adjust the power consumption of the PD 306 at block 350. The second link-layer protocol communication may include a recommendation to the PD 306 to reduce its power consumption so that the PoE power allocated by the PSE 302 is sufficient to continue operation of the PD 306 during the period in which the additional PSE 304 is being serviced. In one example, the PSE 302 may recommend that the PD 306 operate in a low-power mode to reduce power consumption. In response to this recommendation, the PD 306 may communicate to the additional PSE 304 a "minimum power" required to operate in the low-power mode. The "Minimum Power" refers to a minimum power threshold required for the PD 306 to continue routine operation in power saving mode.If the additional PSE 304 confirms that it can supply the "minimum power" to the PD via PoE, the PoE may initiate operation in low-power mode. Based on the recommendation in the second link-layer protocol communication, the PD 306 may adjust the power consumption in block 352. In block 354, the PD 306 may send a link-layer protocol communication to purchase power from the PSE 302 based on the adjusted PD power consumption. This allows the PD 306 to continue operating even though the additional PSE 304 may be undergoing maintenance. Based on the link-layer protocol communication from the PD 306 to the PSE 302, the PSE 302 may change a PSE 302 power allocation for the PD 306. In one example, adjusting the power allocation may include increasing the total PoE power allocated to a PoE-capable port of the PSE 302 connected to the PD 306.This allows the PD 306 to continue operating without interruption even if the PoE configuration of the PSE 302 or the additional PSE 304 changes, the PSE 302 is no longer able to supply PoE to the PD 306, or the additional PSE 304 performs maintenance, a firmware upgrade, or a reboot.

[0075] Now to the Fig. The example methods 400 and 500 are described. The methods 400 and 500 can be executed, for example, by a PSE such as the PSE 105 of Fig. or the PSE 302 from Fig. , as described above. In particular, in some examples, methods 400 and / or 500 may be executed by control circuitry 130 of PSE 105. In some examples, control circuitry 130 includes a computer-readable storage medium storing instructions corresponding to the operations of methods 400 and / or 500, i.e., instructions configured to cause PSE 105 to perform methods 400 and / or 500 when executed by a processor of control circuitry 130. In some examples, control circuitry 130 includes specialized hardware configured to perform methods 400 and / or 500. In some examples, control circuitry 130 is configured to execute methods 400 and / or 500 through a combination of a processor executing instructions and dedicated hardware.

[0076] As in Fig. As shown, the method 400 includes operations of blocks 402 through 438, which are described in more detail below.

[0077] In block 402, the PSE may send a first transport layer protocol communication to an additional PSE. The PSE and the additional PSE are connectable to a PD via respective PoE-capable ports. The first communication from the PSE to the additional PSE includes a first PoE configuration field indicating a PoE configuration of the PSE. The first communication is a transport layer protocol communication, which may be an Ethernet frame containing a source address and TLVs with information. The first PoE configuration field may be one of the TLVs. In one example, the PSE may send the first communication to a management IP address of the additional PSE. In one example, the PoE configuration of the PSE includes the PoE capabilities of the PSE. The PoE capabilities of the PSE include at least one of the following: a power budget of the PSE, a firmware version of the PSE, or a configuration of the PSE's power supply units (PSUs).Although shown first for simplicity, block 402 is not necessarily executed first; for example, block 402 may be executed any time before block 410 or concurrently with block 404. In some examples, the message sent in block 402 may be a subsequent message; for example, the PSE may periodically send transport layer protocol messages to the additional PSE, and block 402 may include such a message.

[0078] In one example, after receiving the first notification, the additional PSE may determine whether it has the capabilities to exchange transport layer protocol communications with the PSE. In response to determining that the additional PSE has the capabilities to exchange transport layer protocol communications, the PSE may receive a second communication from the additional PSE to the PSE in block 404. The second communication includes a second PoE configuration field indicating a PoE configuration of the additional PSE. The second communication is a transport layer protocol communication, which may be an Ethernet frame including a source address and TLVs with information. The second PoE configuration field may be one of the TLVs. In one example, the PSE may receive the first communication from the management IP address of the additional PSE.In one example, the PoE configuration of the additional PSE includes the PoE capabilities of the additional PSE. The PoE capabilities of the additional PSE include at least one of the following: a power budget of the additional PSE, a firmware version of the additional PSE, or a configuration of the PSUs of the additional PSE. In some examples, the communication received in block 404 may be a subsequent communication; for example, the additional PSE may send transport layer protocol communications to the PSE at regular intervals, and block 404 may include such a communication. Thus, the PSE and the additional PSE may exchange a set of transport layer protocol communications that includes the first communication and the second communication.

[0079] In block 406, based on the first and second communications, the PSE may be selected as the main PSE and the additional PSE may be selected as the auxiliary PSE. Once selected as the main PSE, the PSE may announce the configuration of the PoE-capable ports of the PSE in block 408. In one example, the configuration of the PoE-capable ports of the PSE includes at least one of the following: a number of PoE-capable ports, respective power allocations of the PoE-capable ports, respective power consumption amounts of the PoE-capable ports, respective port priorities of the PoE-capable ports, or respective states of the PoE-capable ports of the PSE. In some examples, the PSE may send the configuration of the PoE-capable ports as part of the first communication.For example, in some examples, the announcement in block 408 may be part of the first communication in block 402, where the PSE may send the transport layer protocol communication with the configuration of the PSE's PoE-capable ports to the additional PSE.

[0080] In block 410, the PSE may receive from the additional PSE the configuration of the PoE-capable ports of the additional PSE. In one example, the configuration of the PoE-capable ports of the additional PSE includes at least one of the following: a number of PoE-capable ports, corresponding power allocations of the PoE-capable ports, corresponding power consumption amounts of the PoE-capable ports, corresponding port priorities of the PoE-capable ports, or corresponding states of the PoE-capable ports of the additional PSE. In some examples, the additional PSE may send the configuration of the PoE-capable ports of the additional PSE within the second communication. Thus, in some examples, the communication in block 408 may be part of the second communication received in block 404, where the PSE may receive a transport layer protocol communication with the configuration of the PoE-capable ports of the additional PSE from the additional PSE.

[0081] In block 412, the PSE may create a power availability table from the configuration of the PSE's PoE-capable ports and the configuration of the PoE-capable ports of the additional PSE. In one example, the configuration of the PSE's PoE-capable ports and that of the additional PSE may be obtained from the first and second PoE configuration fields in the first and second messages exchanged between the PSE and the additional PSE in blocks 402 and 404. Thus, the power availability table may be created based on information from the first PoE configuration field and the second PoE configuration field.

[0082] In block 414, the PSE may send a copy of the power availability table to another PSE for storage. In some examples, blocks 408, 410, and 412 may be repeated periodically. This means that any changes in the configuration of the PoE-capable ports of the PSE or the additional PSE may be incorporated into an updated version of the power availability table. The entries in the power availability table may be compared with the entries in the updated version of the power availability table to determine, in block 416, whether a change has occurred in the power availability table.

[0083] Furthermore, in some examples, blocks 402 and 404 may be repeated periodically. The first communication may be compared to a subsequent first communication to check whether there are changes between the first PoE configuration field in the first communication and that in the subsequent first communication. Likewise, the second communication may be compared to a subsequent second communication to check whether there are changes between the second PoE configuration field in the second communication and that in the subsequent second communication. Based on this, the PSE may check in block 418 whether there is a change in the power budget or the PSU configuration.

[0084] In block 420, the PSE may check whether it has received keep-alive messages from the additional PSE. As in Fig. As shown, the operations in blocks 416, 418, and 420 may be performed concurrently. In another example, the operations in blocks 416, 418, and 420 may be performed sequentially one after the other. If it is determined that there is no change in the power availability table ("No" branch from block 416), the PSE may determine in block 422 that no event has occurred. Likewise, if it is determined that there is no change in the power budget or PSU configuration ("No" branch starting at block 418), the PSE may determine in block 422 that no event has occurred. Also, if it is determined that a keep-alive message is received from the additional PSE within a keep-alive interval ("YES" branch from block 420), the PSE may determine in block 422 that no event has occurred.

[0085] In response to determining that there is a change in the power availability table ("YES" branch of block 416), the PSE may determine that an event has occurred in block 424. In response to determining a change in the power budget or PSU configuration ("YES" branch of block 418), the PSE may also determine that an event has occurred in block 424. Likewise, in response to determining that no keep-alive communication was received in the keep-alive interval ("NO" branch starting at block 420), the PSE may determine that an event has occurred in block 424. In one example, the event includes at least one of a change in the power availability table and a change in the PSE's ability to supply power to the PD.In response to detecting the occurrence of the event, the PSE can send a transport-layer protocol communication to the additional PSE to notify the occurrence of the event. The transport-layer protocol communication includes a TLV that specifies the type of event, such as planned maintenance, a change in the configuration of the PSE's or additional PSE's PoE-capable ports that results in a change in the PSE's power availability table, a change in the PSE's power budget, or a change in the PSE's PSU configuration.

[0086] In response to determining that there is a change in the power availability table ("YES" branch of block 416), the PSE may check in block 426 whether the port priority of a PSE port connected to the PD has been decreased. Decreasing the port priority includes changing the port priority from "critical" to "high" or from "high" to "low," where "critical" priority corresponds to the highest priority of a PoE-capable port and "low" corresponds to the lowest priority of a PoE-capable port. In response to determining that the port priority has not been decreased ("No" branch of block 426), the PSE may check in block 428 whether other entries in the power availability table have changed, such as the power class and the consumed PoE power.In response to determining that the port priority has been decreased ("Yes" branch of block 426), the PSE checks whether the port of the additional PSE connected to the PD has "high" priority in block 430. In response to determining that the port of the additional PSE connected to the PD does not have "high" priority, the PSE sends a transport layer protocol communication to the additional PSE in block 432. The transport layer protocol message may include a request to the additional PSE to increase the port priority of the port of the additional PSE connected to the PD. In response to determining that the port of the additional PSE connected to the PD has "high" priority, the PSE sends another transport layer protocol communication to the additional PSE in block 434.The other transport layer protocol communication comprises a request to the additional PSE to adjust a power allocation of the additional PSE for the PD. In one example, adjusting the power allocation of the additional PSE for the PD comprises increasing the power allocation of the additional PSE for the PD. In response to determining that there is a change in the PSE's power budget or PSU configuration ("YES" branch of block 418), the PSE sends the other transport layer protocol communication to the additional PSE in block 434, wherein the other transport layer protocol communication comprises a request to the additional PSE to adjust a power allocation of the additional PSE for the PD.

[0087] In response to determining that the keep-alive communication from the additional network operator is not received in consecutive keep-alive intervals ("NO" branch of block 420), the network operator sends a first link-layer communication to the PD in block 436 indicating that the additional network operator is going into maintenance. In block 438, the PSE sends a second link-layer communication to the PD. The second link-layer message includes a request to adjust at least one of the PD's power query, signature, and power class components.

[0088] As in Fig. As shown, method 500 includes operations of blocks 502 through 508. Method 500 is a modification of method 400.

[0089] In block 502, the PSE exchanges a first set of transport layer protocol communications with an additional PSE. The additional PSE includes a port connectable to a PD via a communication link to power and communicate with the PD. The additional PSE is also connected to the PD to provide PoE to the PD. The first set of transport layer protocol communications includes a first communication from the PSE to the additional PSE and a second communication from the additional PSE to the PSE. The first communication includes a first PoE configuration field indicating a PoE configuration of the PSE, and the second communication includes a second PoE configuration field indicating a PoE configuration of the additional PSE.

[0090] In block 504, the PSE creates a power availability table for the PD based on information from the first PoE configuration field and the second PoE configuration field. The power availability table is an indicator of the availability of PoE for the PD from the PSE and the additional PSE.

[0091] In block 506, the PSE detects the occurrence of an event that includes at least one change in the power availability table or a change in the PSE's ability to supply power to the PD.

[0092] In block 508, the PSE sends a second set of transport-layer protocol communications to the additional PSE, based at least in part on the event. The second set of transport-layer protocol communications includes a request to the additional PSE to adjust a power allocation of the additional PSE for the PD.

[0093] In Fig. An example of a non-transitory computer-readable storage medium 600 (storage medium 600) will now be described. The storage medium 600 stores instructions 602 to 608 that are executed by a processor of a PSE (e.g., a processor of the control circuit 130 of the PSE 105 of Fig. ) to cause the PSE to perform various operations described herein. In some examples, the storage medium 600 is part of a PSE, such as the PSE 105. For example, in some embodiments, the storage medium 600 is part of the control circuitry 130, and the control circuitry 130 further includes a processor coupled to the storage medium 600 and configured to read and execute the instructions 602-608. In some embodiments, the storage medium 600 may be provided as a computer program product that is at least initially separate from a PSE.The computer program product may be used to program a PSE to perform operations associated with instructions 602 through 608, for example, by transferring instructions 602 through 608 from storage medium 600 to the PSE, either for copying to local memory on the PSE or for immediate execution by the PSE.

[0094] Instructions 602 include instructions for exchanging a first set of transport layer protocol communications with an additional PSE. The additional PSE is connected to the PD to provide PoE to the PD. The first set of transport layer protocol communications includes a first communication from the PSE to the additional PSE including a first PoE configuration field indicating a PoE configuration of the PSE, and a second communication from the additional PSE to the PSE including a second PoE configuration field indicating a PoE configuration of the additional PSE. In one example, instructions 602 may include instructions for performing operation 135 and other related operations as described above with respect to the PSE 105 in Fig. Instructions 602 may also include operations described above with respect to blocks 402, 404 of method 400 and block 502 of method 500.

[0095] Instructions 604 include instructions for creating a power availability table for the PD based on information from the first PoE configuration field and the second PoE configuration field, wherein the power availability table indicates the availability of PoE for the PD from the PSE and the additional PSE. For example, instructions 604 may include instructions for performing operation 140 and other related operations described above with respect to the PSE 105 in Fig. Instructions 604 may also include operations described above with respect to blocks 408, 410, 412, and 414 of method 400 and / or block 504 of method 500.

[0096] The instructions 606 include instructions for detecting the occurrence of an event that includes at least one change in the power availability table or a change in the ability of the PSE to supply power to the PD. For example, the instructions 606 may include instructions for performing operation 150 and other related operations described above with respect to the PSE 105 in Fig. Instructions 606 may also include operations described above with respect to blocks 416, 418, and 420 of method 400 and / or block 506 of method 500.

[0097] Instructions 608 include instructions for sending, based at least in part on the occurrence of the event, a second set of transport layer protocol communications to the additional PSE, wherein the second set of transport layer protocol communications includes a request to the additional PSE to adjust a power allocation of the additional PSE for the PD. For example, instructions 608 may include instructions for performing operation 155 and other related operations described above with respect to the PSE 105 in Fig. Instructions 608 may also include operations described above with respect to blocks 430 and 432 of method 400 and / or block 508 of method 500.

[0098] In Fig. An example of a non-transitory, computer-readable storage medium 700 (storage medium 700) will now be described. The storage medium 700 stores instructions 702 through 710 that can be executed by a processor of a PD (e.g., a processor of the control circuitry 220 of the PD 200) to cause the PD to perform various operations described herein. In some examples, the storage medium 700 is part of a PD, such as the PD 200. For example, in some embodiments, the storage medium 700 is part of the control circuitry 220, and the control circuitry 220 further includes a processor coupled to the storage medium 700 and configured to read and execute the instructions 702 and 704. In some embodiments, the storage medium 700 can be provided as a computer program product that is at least initially separate from a PD.The computer program product may be used to program a PD to perform operations associated with instructions 702 and 704, for example, by transferring instructions 702 and 704 from storage medium 700 to the PD to copy them into the PD's local memory or to have them executed immediately by the PD.

[0099] Instructions 702 include instructions for receiving power from a first PSE via an Ethernet cable plugged into a first uplink port of the PD. Instructions 702 may include instructions for performing operation 202 and other related operations described above with respect to the PD 200 in Fig. were described.

[0100] Instructions 704 include instructions for receiving power from a second PSE via a different Ethernet cable plugged into a second uplink port. Instructions 704 may include instructions for performing operations 224 and other related operations described above with respect to PD 200 in Fig. were described.

[0101] Instructions 706 include instructions for receiving a first link-layer protocol communication from the first PSE in response to the occurrence of an event that includes at least one of a change in a power availability table of the PD or a change in the PSE's ability to power the PD. The first link-layer protocol communication is an indication of a request to adjust PD power consumption. Instructions 706 may include instructions for performing operations 226 and other related operations described above with respect to the PD 200 in Fig. were described.

[0102] Instructions 708 include instructions for adjusting the power consumption of the PD based on the first link layer protocol communication. Instructions 708 may include instructions for performing operations 228 and other related operations described above with respect to the PD 200 in Fig. were described.

[0103] Instructions 710 include instructions for sending a second link-layer protocol communication to the second PSE to obtain power from the second PSE based on the adjusted PD power consumption. Instructions 710 may include instructions for performing operations 230 and other related operations described above with respect to the PD 200 in Fig. were described.

[0104] The above description describes various types of electronic circuits. The term "electronic" used here is broad and encompasses all types of circuits that use electricity, including digital and analog circuits, direct current (DC) and alternating current (AC) circuits, as well as circuits that convert electricity into another form of energy and circuits that use electricity to perform other functions. In other words, no distinction is made here between "electronic" circuits and "electrical" circuits.

[0105] It should be understood that both the general description and the detailed description include examples that are explanatory and are intended to aid understanding of the present disclosure without limiting the scope of the present disclosure. Various mechanical, compositional, structural, electronic, and operational changes may be made without departing from the scope of this description and the claims. In some instances, well-known circuits, structures, and techniques have not been shown or described in detail in order not to obscure the examples. Like numerals in two or more figures represent like or similar elements.

[0106] Furthermore, the singular forms "a," "an," and "the" include the plural forms unless the context indicates otherwise. Furthermore, the terms "comprises," "includes," "includes," and the like specify the presence of certain features, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and / or groups. Components described as coupled may be directly coupled electronically or mechanically, or they may be indirectly coupled through one or more intermediate components, unless expressly stated otherwise.Mathematical and geometric terms need not necessarily be used in accordance with their strict definitions unless the context of the description suggests otherwise, because a person having ordinary technical knowledge would understand that, for example, an essentially similar element functioning in an essentially similar manner could easily fall within the scope of a descriptive term, even if the term also has a strict definition.

[0107] And / or: Occasionally, the term "and / or" is used here in connection with a list of items. This wording means that any combination of items in the list—from a single item to all items and every permutation in between—can be included. For example, "A, B, and / or C" means "one of {A}, {B}, {C}, {A, B}, {A, C}, {C, B}, and {A, C, B}."

[0108] Elements and their associated aspects that are described in detail in one example may, whenever practical, be included in other examples in which they are not specifically shown or described. For example, if an element is described in detail with reference to one example and not described with reference to a second example, the element may still be claimed as included in the second example.

[0109] Unless otherwise noted herein or apparent from the context, the use of terms of approximation such as "substantially," "approximately," "about," "approximately," "approximately," and the like is intended to eliminate the requirement of mathematical precision and instead to refer to a range of variation including, but not strictly limited to, the stated value, property, or relationship. In particular, the range of variation implied by the use of such an approximation shall include, in addition to the ranges of variation explicitly stated herein (if any), at least all immaterial variations and also variations that are typical in the relevant art for the type of article in question due to manufacturing or other tolerances.In any case, the variation range may include at least values ​​within ±1% of the stated value, property or ratio, unless otherwise stated.

[0110] Further modifications and alternative examples will be apparent to those skilled in the art in light of the present disclosure. For example, the devices and methods may include additional components or steps that have been omitted from the diagrams and descriptions for clarity. Accordingly, this description is intended to be illustrative only and is intended to teach those skilled in the art the general manner of carrying out the present teachings. The various examples shown and described herein are to be considered exemplary.Elements and materials, as well as arrangements of these elements and materials, may be used instead of those shown and described herein, parts and methods may be reversed, and certain features of the present teachings may be used independently, as would be apparent to one skilled in the art after reviewing this description. Changes may be made to the elements described herein without departing from the scope of the present teachings and the following claims.

[0111] It is to be understood that the examples set forth herein are not limiting and that changes in structure, dimensions, materials and processes may be made without departing from the scope of the present teachings.

[0112] Further examples consistent with the present disclosure will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. It is intended that the specification and examples be considered as exemplary only, with the following claims being given the full breadth, including equivalents, under applicable law.< / klasse> < / version> < / name>

Claims

[1] Power supply equipment (PSE), consisting of: a first port connectable to a powered device (PD) via a first communication link to supply power over Ethernet (PoE) to the PD and exchange communication with it; a second port connectable to an additional PSE via a second communication link; and a control circuit configured to connect the PD to the second terminal in a state where the PD is connected to the first terminal and the additional PSE is connected to the second terminal: Exchanging a first set of transport layer protocol communications with the additional PSE, the additional PSE being connected to the PD to provide PoE to the PD, the first set of transport layer protocol communications comprising: a first message from the PSE to the additional PSE containing a first PoE configuration field indicating a PoE configuration of the PSE; and a second communication from the additional PSE to the PSE including a second PoE configuration field indicating a PoE configuration of the additional PSE; Generating a power availability table for the PD based on information from the first PoE configuration field and the second PoE configuration field, the power availability table indicating the availability of PoE for the PD from the PSE and the additional PSE; Detecting the occurrence of an event that includes at least one change in the energy availability table or a change in the ability of the PSE to supply energy to the PD; and Sending, based at least in part on the occurrence of the event, a second set of transport layer protocol communications to the additional PSE, wherein the second set of transport layer protocol communications comprises a request to the additional PSE to adjust a power allocation of the additional PSE for the PD. [2] The PSE of claim 1, wherein to exchange the first set of transport layer protocol communications with the additional PSE, the control circuit is configured to: send the first message to a management Internet Protocol (IP) address of the additional PSE; and to receive the second communication from the management IP address of the additional PSE. [3] The PSE of claim 1, wherein the PoE configuration of the PSE includes PoE capabilities of the PSE. [4] The PSE of claim 3, wherein the PoE capabilities of the PSE comprise at least one of the following: a power budget of the PSE, a firmware version of the PSE, or a configuration of power supply units (PSUs) of the PSE. [5] The PSE of claim 1, wherein the PoE configuration of the PSE comprises a configuration of PoE-enabled ports of the PSE. [6] according to claim 5, wherein the configuration of the PoE-capable ports of the PSE comprises at least one of the following elements: a number of PoE-capable ports, respective power allocations of the PoE-capable ports, respective power consumption amounts of the PoE-capable ports, respective port priorities of the PoE-capable ports, or respective states of the PoE-capable ports. [7] The PSE of claim 1, wherein changing the ability of the PSE to power the PD comprises reducing the number of power supply units (PSUs) connected to the PSE. [8] The PSE of claim 7, wherein the second set of transport layer protocol communications comprises a control communication to the additional PSE indicating to the additional PSE to increase the power allocation of the additional PSE for the PD in response to the decrease in the number of PSUs connected to the PSE. [9] The PSE of claim 1, wherein changing the ability of the PSE to supply power to the PD comprises reducing PoE power availability at the PSE. [10] The PSE of claim 9, wherein the second set of transport layer protocol communications comprises a control communication to the additional PSE indicating to the additional PSE to increase the power allocation of the additional PSE for the PD in response to the reduction in PoE power availability at the PSE. [11] The PSE of claim 1, wherein the change in the power availability table comprises a reduction in the PoE port priority of a PoE-capable port of the PSE connected to the PD. [12] The PSE of claim 11, wherein to transmit the second set of transport layer protocol communications, the control circuit is configured to: Check the power availability table to see if a port of the additional PSE connected to the PD has a high priority; in response to determining that the port of the additional PSE does not have high priority, send a control communication to the additional PSE indicating to the additional PSE to increase the port priority of the port; and in response to determining that the connection of the additional PSE has the high priority, send a further control communication to the additional PSE, the further control communication indicating a request to the additional PSE to increase the power allocation of the additional PSE for the PD. [13] The PSE of claim 1, wherein, to detect the occurrence of the event, the control circuit is configured to check whether transport layer protocol communications including keep-alive communications are received by the additional PSE. [14] The PSE of claim 1, wherein the control circuit is further configured, in response to detecting the event, to: Sending a first link-layer protocol communication to the PD, wherein the first link-layer protocol communication indicates to the PD that the additional PSE is being serviced; and Sending a second link layer protocol communication to the PD, wherein the second link layer protocol communication indicates a request to the PD to adjust at least one of the power requirement, the PD signature configuration, and the PD power class so that the operation of the PD is uninterrupted. [15] Method for managing Power over Ethernet (PoE), which includes: Exchanging a first set of transport layer protocol communications with an additional PSE through a power source equipment (PSE), the PSE and the additional PSE being configured to provide PoE to a powered device (PD), the first set of transport layer protocol communications comprising: a first message from the PSE to the additional PSE containing a first PoE configuration field indicating a PoE configuration of the PSE; and a second communication from the additional PSE to the PSE including a second PoE configuration field indicating a PoE configuration of the additional PSE; Generating a power availability table for the PD based on information from the first PoE configuration field and the second PoE configuration field, the power availability table indicating the availability of PoE for the PD from the PSE and the additional PSE; Detecting the occurrence of an event that includes at least one change in the energy availability table or a change in the ability of the PSE to supply energy to the PD; and Sending, based at least in part on the occurrence of the event, a second set of transport layer protocol communications to the additional PSE, wherein the second set of transport layer protocol communications comprises a request to the additional PSE to adjust a power allocation of the additional PSE for the PD. [16] The method of claim 15, wherein exchanging the first set of transport layer protocol communications with the additional PSE comprises: Sending the first message to an Internet Protocol (IP) management address of the additional PSE; and Receiving the second message from the management IP address of the additional PSE. [17] The method of claim 15, wherein the PoE configuration of the PSE comprises PoE capabilities of the PSE. [18] The method of claim 17, wherein the PoE capabilities of the PSE comprise at least one of: a power budget of the PSE, a firmware version of the PSE, or a configuration of power supply units (PSUs) of the PSE. [19] Powered device (PD) comprising: a control circuit; a first uplink connection; a second uplink connection; and a control circuit configured to, in a state where the first uplink port is connected to a first power supply device (PSE) and the second uplink port is connected to a second PSE: receive power from the first PSE via an Ethernet cable plugged into the first uplink port; receive power from the second PSE via another Ethernet cable plugged into the second uplink port; Receiving a first link-layer protocol communication from the first PSE in response to the occurrence of an event comprising at least one of a change in a power availability table of the PD and a change in the ability of the PSE to power the PD, the first link-layer protocol communication indicating a request to adjust PD power consumption, the power availability table indicating the availability of PoE for the PD based on the PoE configuration of the first PSE and the PoE configuration of the second PSE; adjust the PD power consumption based on the first link layer protocol communication; and Sending a second link layer protocol communication to one of the PSEs or the second PSE to source power based on the adjusted PD power consumption. [20] The PD of claim 19, wherein the control circuit is configured to switch the PD from a normal mode to a power saving mode in response to receiving the first link layer protocol communication.

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