Patent Description:
The present teachings relate to a method, routing device, network device, and computer readable medium for using a flex-algorithm in heterogeneous networks.

In segment routing, traffic is communicated through a network via a segment routing path. The segment routing path is an ordered list of segments that connect a source (e.g., an ingress node of the network) and a destination (e.g., an egress node of the network). An individual segment of the list of segments (referred to as a "prefix segment") follows a least-cost path from a source of the prefix segment to a destination of the prefix segment.

The document "<NPL>) as obtained by the EPO (date of retrieval by EPO <NUM>/<NUM>/<NUM>) from the URL https://tools. org/html/draft-ietf-lsr-flex-algo-<NUM> is a draft implementation of the IGP Flexible Algorithm by the Network Working Group of the Internet Engineering Task Force.

<CIT> discloses techniques for facilitating the inclusion of a non-flexible algorithm router to be included in flexible-algorithm computations, For example, a flexible-algorithm router advertises information associated with a non-flexible algorithm router to other flexible-algorithm routers in the network such that the flexible-algorithm routers may include the non-flexible algorithm router when computing a path based on flexible-algorithm. During path computation, if the router determines that its next-hop router is the non-flexible-algorithm router, the router may configure additional forwarding information to cause the router to steer traffic to the non-flexible-algorithm router.

The present disclosure includes example arrangements falling within the scope of the claims (and other arrangements may also be within the scope of the claims) and may also include example arrangements that do not necessarily fall within the scope of the claims but which are then useful to understand the invention and the teachings and techniques provided herein. In some implementations, a method comprises receiving, by a first network device, an advertisement from a second network device, wherein the advertisement is associated with indicating that the second network device is configured to support a particular flex-algorithm, and wherein the first and second devices are included in a non-segment routing capable network, identifying, by the first network device and in the advertisement, an address of the second network device; configuring, by the first network device, a routing table of the first network device to indicate that the second network device is capable of receiving traffic associated with the particular flex-algorithm based on the address; and performing, by the first network device and using the routing table, an action associated with routing the traffic associated with the particular flex-algorithm.

In some implementations, a network device includes one or more memories and one or more processors to receive, via a non-segment-routing network, information associated with a flexible algorithm; associate a loopback address with the flexible algorithm based on receiving the information associated with the flexible algorithm; provide, to one or more other network devices included in the non-segment-routing network, information indicating that the loopback address is associated with the flexible algorithm; and receive network traffic associated with the flexible algorithm based on providing the information indicating that the loopback address is associated with the flexible algorithm to the one or more other network devices.

In some implementations, a transitory or non-transitory computer-readable medium storing a set of instructions includes one or more instructions that, when executed by one or more processors of a first network device, cause the first network device to receive an advertisement from a second network device, wherein the advertisement is associated with indicating that the second network device is configured to support a particular flex-algorithm, wherein the first and second network devices are both included in a non-segment routing capable network, identify, in the advertisement, an address of the second network device; configure a routing table of the first network device to indicate that the second network device is capable of receiving traffic associated with the particular flex-algorithm based on the address; and perform, using the routing table, an action associated with routing the traffic associated with the particular flex-algorithm.

A network that uses segment routing may utilize a routing protocol (e.g., an Intradomain Gateway Protocol (IGP)) to calculate and/or identify a least-cost path for transmitting traffic via the network. Segment routing may enable multiple prefix segments, ending at a same destination, to be configured in the network.

A flex-algorithm may be used in segment routing to influence how the routing protocol calculates the least-cost path for each prefix segment. For example, nodes (e.g., network devices) included in a segment routing network may indicate a flex-algorithm with a prefix segment identifier (SID) (e.g., for segment routing multiprotocol label switching (SR-MPLS)) or may indicate the flex-algorithm with a flex-algorithm locator (e.g., an SRv6 locator). A set of prefix SIDs and/or flex-algorithm locators may then represent a segment routing path that is computed according to the identified flex-algorithm. However, some networks are not configured for segment routing and, therefore, may not enable use of a flex-algorithm.

The implementations described herein enable use of flex-algorithms in networks that do not use segment routing (referred to herein as "non-segment-routing networks"). For example, as described herein, a network device that is configured to route traffic according to a flex-algorithm definition (e.g., a flex-algorithm that is defined by a particular set of parameters, constraints, and/or the like) may advertise, to other network devices of the non-segment-routing network (e.g., neighbor network devices and/or other peer network devices of the network), an identifier for the flex-algorithm definition (referred to herein as a "Flex-Algo ID") and a specific address (e.g., a secondary address, a loopback address, and/or the like) of the network device that is designated to receive traffic associated with the flex-algorithm definition. Further, if a network device is configured to use multiple flex-algorithms, the network device may associate each of the multiple flex-algorithms with a respective address (e.g., each flex-algorithm may be mapped to a unique loopback address of the network device).

As described herein, for a particular flex-algorithm definition, the network devices (e.g., all network devices and/or a plurality of network devices) of the non-segment-routing network may calculate a least-cost path (e.g., according to the IGP) for transmitting traffic, associated with the flex-algorithm definition, between a source device and a destination device of the non-segment-routing network. The least-cost path may be determined based on costs calculated for links to addresses (e.g., of peer network devices), according to the flex-algorithm definition, that have been advertised for use with the flex-algorithm definition.

In this way, as the network devices of the non-segment-routing network advertise, to other network devices, corresponding addresses for flex-algorithms that the network devices are configured to support to calculate costs, the network devices may select and/or identify route paths for the flex-algorithms based on the addresses. Accordingly, network devices in a non-segment-routing network using a flex-algorithm, as described herein, may not need to analyze whether a segment of the network device satisfies the constraints of the flex-algorithm, because the network devices are only aware of links to addresses that are associated with the flex-algorithm. A route path, between a source device and a destination device, for a flex-algorithm may be configured using addresses of the network devices that use the flex-algorithm.

<FIG> are diagrams of an example <NUM> associated with a configuration of a non-segment-routing network that uses a flex-algorithm routing mechanism. As shown in <FIG>, example <NUM> includes a set of network devices (shown as and referred to individually in connection with example <NUM> as "R1," "R2," and "R3," and collectively as the "network devices") of a network, a source device, and a destination device. The network devices may be peer nodes of the network. In some implementations, R1 is a neighbor node of R2 and R3. The source device and the destination device may be user devices and/or network devices.

As shown in <FIG>, and by reference number <NUM>, R1 receives link information from R2 and R3. For example, R2 and/or R3 may use an intermediate system to intermediate system (IS-IS) routing protocol and/or an open shortest path first (OSPF) routing protocol to advertise information associated with R2 and/or R3 and/or link information associated with links to which R2 and/or R3 are connected. The link information for a link may include one or more metrics for calculating a least cost path (e.g., an IGP metric, a traffic engineering (TE) metric, a minimum unidirectional link delay metric, and/or the like), information identifying an administrative group (e.g., a low latency group that includes links associated with low latencies, a high latency group, a low bandwidth group, a high bandwidth group, and/or the like) associated with the link, and/or the like.

As shown by reference number <NUM>, R1 configures a link state data structure (e.g., a database, a table, a list, and/or the like) based on the link information received from R2 and/or R3. R1 may utilize the information stored in the link state data structure to calculate a cost associated with transmitting a packet from R1 to R2, from R1 to R3, from R2 to R3, and/or the like. R1 may utilize the calculated costs to determine a least cost path for transmitting traffic through the network.

As shown in <FIG>, and by reference number <NUM>, R1 receives flex-algorithm advertisements from R2 and R3. For example, R2 and/or R3 may utilize the IS-IS routing protocol, the OSPF routing protocol, and/or the like to advertise one or more flex-algorithm definitions and/or links associated with a particular flex-algorithm. A flex-algorithm definition may include a Flex-Algo ID associated with the flex-algorithm definition, information identifying a type of metric (e.g., an IGP metric, a TE metric, a minimum unidirectional link delay metric, and/or the like) associated with calculating a least cost path, information identifying a calculation type (e.g., shortest path first (SPF), strict SPF, and/or the like) associated with calculating a least cost path, and/or information identifying one or more constraints associated with calculating a least cost path (e.g., include all administrative groups, exclude links associated with a particular administrative group, only include links associated with a particular administrative group, and/or the like).

In some implementations, the advertisement from R2 includes Flex-Algo IDs of the flex-algorithm definitions used by R2 and corresponding addresses through which R2 is to receive traffic associated with the respective flex-algorithm definitions. Similarly, the advertisement from R3 may include Flex-Algo IDs of the flex-algorithm definitions used by R3 and corresponding addresses through which R3 is to receive traffic associated with the respective flex-algorithm definitions.

As shown more specifically, R2 may be configured to receive traffic associated with a flex-algorithm definition identified by Flex-Algo ID "<NUM>" via an address interface identified by address "<NUM>. <NUM>" and may receive traffic associated with a flex-algorithm definition identified by Flex-Algo ID "<NUM>" via an address interface identified by address "<NUM>. " Furthermore, R3 may be configured to receive traffic associated with a flex-algorithm definition identified by Flex-Algo ID "<NUM>" via an address interface identified by address "<NUM>. <NUM>" and may receive traffic associated with a flex-algorithm definition identified by Flex-Algo ID "<NUM>" via an address interface identified by address "<NUM>. " In this way, R1 may receive flex-algorithm advertisements from R2 and R3 to permit R1 to configure a routing table for non-segment routing of flex-algorithm traffic through the network.

In some implementations, the corresponding addresses through which R2 and/or R3 are to receive traffic associated with the respective flex-algorithm definitions comprise loopback addresses. A loopback address may correspond to a software loopback interface of a network interface card (e.g., a network interface card of R2 and/or R3). The software loopback interface may not be associated with hardware and may not require a physical connection to the network.

As further shown in <FIG>, and by reference number <NUM>, R1 configures a flex-algorithm table based on the received flex-algorithm advertisements. As shown, the flex-algorithm table maps Flex-Algo IDs to corresponding addresses associated with R2 and R3.

According to some implementations, and as shown in example <NUM>, R1 may be configured to use flex-algorithms identified by Flex-Algo IDs "<NUM>," "<NUM>," and "<NUM>. " In some implementations, R1 may only include entries for Flex-Algo IDs in the table that are associated with flex-algorithms that R1 is configured to support for routing traffic via the network. For example, if R1 were not configured to route traffic according to the flex-algorithm identified by Flex-Algo ID "<NUM>," R1 may not add an entry according to the advertisement from R2 that identifies Flex-Algo ID "<NUM>" and address "<NUM>. " In this way, R1 configures a flex-algorithm routing table for routing of flex-algorithm traffic, in a non-segment-routing network, using addresses of R2 and R3.

As shown in <FIG>, and by reference number <NUM>, R1 determines a cost associated with links to the addresses of R2 and R3 according to corresponding flex-algorithms of the addresses. For example, R1 may use an IGP metric, a TE metric, and/or the like to determine the costs. Additionally, or alternatively, R1 may determine the costs based on one or more parameters, constraints, and/or the like of the flex-algorithms. R1 may determine a cost associated with links to the addresses of R2 and R3 for each flex-algorithm. In this way, R1 may determine costs of routing traffic associated with the individual flex-algorithms to R2 and R3, to permit R1 to use the flex-algorithms for non-segment routing.

As further shown in <FIG>, and by reference number <NUM>, R1 receives flex-algorithm traffic that identifies a destination address (shown as "Dest_Addr") of the destination device. The flex-algorithm traffic is to be transmitted from the source device to the destination device. Accordingly, the traffic may include a first packet (shown as "<NUM> traffic," which may be associated with Flex-Algo ID "<NUM>") with a source address (shown as "Src_Addr") of the source device, the destination address of the destination device, and a payload (shown as "Payload_128"). Further, the traffic may include a second packet (shown as "<NUM> traffic," which may be associated with Flex-Algo ID "<NUM>") with the source address, the destination address, and a payload (shown as "Payload_129"). In this way, R1 receives flex-algorithm traffic, to permit R1 to route the traffic to R2 and/or R3 using the flex-algorithm routing table.

As further shown in <FIG>, and by reference number <NUM>, R1 forwards the traffic toward the destination device using the routing table. For example, R1 may forward the first packet toward the destination device via R2. R1 may have selected R2, rather than R3, for sending the first packet based on the cost of non-segment routing flex-algorithm traffic to R2 being less than the cost of non-segment routing traffic to R3 (e.g., "<NUM>" < "<NUM>"). As another example, R1 may forward the second packet toward the destination device via R3. R1 may have selected R3, for sending the second packet based on R3 being the only peer router on a path toward the destination device that processes flex-algorithm traffic identified by Flex-Algo ID "<NUM>".

Alternatively, and/or additionally, R1 may forward the second packet toward the destination device via R3 based on a constraint included in a flex-algorithm definition. For example, a constraint included in a flex-algorithm definition may indicate that links associated with an administrative group (e.g., Group <NUM>, as shown in <FIG>) are to be excluded. R1 may forward the second packet toward the destination device via R3 based on the constraint indicating that the links associated with the administrative group are to be excluded. In this way, R1 may perform non-segment routing of flex-algorithm traffic using loopback addresses of R2 and R3 that are designated for specific flex-algorithms.

<FIG> is a diagram of an example environment <NUM> in which systems and/or methods described herein may be implemented. As shown in <FIG>, environment <NUM> may include a source device <NUM>, a destination device <NUM>, a network <NUM>, and one or more network devices <NUM> (referred to herein individually as network device <NUM> or collectively as network devices <NUM>). The devices of environment <NUM> may interconnect via wired connections, wireless connections, or a combination of wired and wireless connections.

The source device <NUM> and/or the destination device <NUM> may include one or more user devices. For example, the source device <NUM> and/or the destination device <NUM> may include one or more devices capable of receiving, generating, storing, processing, and/or providing network traffic associated with an application and/or a session, as described herein. The source device <NUM> and/or the destination device <NUM> may include a communication and/or computing device, such as a mobile phone (e.g., a smart phone, a radiotelephone, and/or the like), a laptop computer, a tablet computer, a handheld computer, a desktop computer, a gaming device, a wearable communication device (e.g., a smart wristwatch, a pair of smart eyeglasses, and/or the like), or a similar type of device.

In some implementations, the source device <NUM> and/or the destination device <NUM> may be a cloud-based platform of a cloud computing environment, a web-based platform, an online platform, and/or the like. In some implementations, the source device <NUM> and/or the destination device <NUM> include a network device, such as the network device <NUM>, described in greater detail below.

The network <NUM> includes one or more wired and/or wireless networks. For example, the network <NUM> may include a cellular network (e.g., a long-term evolution (LTE) network, a code division multiple access (CDMA) network, a <NUM> network, a <NUM> network, a <NUM> network, another type of next generation network, etc.), a public land mobile network (PLMN), a local area network (LAN), a wide area network (WAN), a metropolitan area network (MAN), a telephone network (e.g., the Public Switched Telephone Network (PSTN)), a private network, an ad hoc network, an intranet, the Internet, a fiber optic-based network, a cloud computing network, or the like, and/or a combination of these or other types of networks.

The network device <NUM> includes one or more devices (e.g., one or more traffic transfer devices) capable of processing and/or transferring traffic between endpoint devices (e.g., the source device <NUM> and the destination device <NUM>). For example, network device <NUM> may include a firewall, a router, a gateway, a switch, a hub, a bridge, a reverse proxy, a server (e.g., a proxy server), a security device, an intrusion detection device, a load balancer, or a similar device. In some implementations, the network device <NUM> may be a physical device implemented within a housing, such as a chassis. In some implementations, the network device <NUM> may be a virtual device implemented by one or more computer devices of a cloud computing environment or a data center.

The number and arrangement of devices and networks shown in <FIG> are provided as one or more examples.

<FIG> is a diagram of example components of a device <NUM>, which may correspond to the source device <NUM>, the destination device <NUM>, and/or the network device <NUM>. In some implementations, the source device <NUM>, the destination device <NUM>, and/or the network device <NUM> may include one or more devices <NUM> and/or one or more components of the device <NUM>. As shown in <FIG>, the device <NUM> may include a bus <NUM>, a processor <NUM>, a memory <NUM>, a storage component <NUM>, an input component <NUM>, an output component <NUM>, and a communication component <NUM>.

The bus <NUM> includes a component that enables wired and/or wireless communication among the components of the device <NUM>. The processor <NUM> includes a central processing unit, a graphics processing unit, a microprocessor, a controller, a microcontroller, a digital signal processor, a field-programmable gate array, an application-specific integrated circuit, and/or another type of processing component. The processor <NUM> is implemented in hardware, firmware, or a combination of hardware and software. In some implementations, the processor <NUM> includes one or more processors capable of being programmed to perform a function. The memory <NUM> includes a random access memory, a read only memory, and/or another type of memory (e.g., a flash memory, a magnetic memory, and/or an optical memory).

The storage component <NUM> stores information and/or software related to the operation of the device <NUM>. For example, the storage component <NUM> may include a hard disk drive, a magnetic disk drive, an optical disk drive, a solid state disk drive, a compact disc, a digital versatile disc, and/or another type of non-transitory computer-readable medium. The input component <NUM> enables the device <NUM> to receive input, such as user input and/or sensed inputs. For example, the input component <NUM> may include a touch screen, a keyboard, a keypad, a mouse, a button, a microphone, a switch, a sensor, a global positioning system component, an accelerometer, a gyroscope, an actuator, and/or the like. The output component <NUM> enables the device <NUM> to provide output, such as via a display, a speaker, and/or one or more light-emitting diodes. The communication component <NUM> enables the device <NUM> to communicate with other devices, such as via a wired connection and/or a wireless connection. For example, the communication component <NUM> may include a receiver, a transmitter, a transceiver, a modem, a network interface card, an antenna, and/or the like.

The device <NUM> may perform one or more processes described herein. For example, a non-transitory computer-readable medium (e.g., the memory <NUM> and/or the storage component <NUM>) may store a set of instructions (e.g., one or more instructions, code, software code, program code, and/or the like) for execution by the processor <NUM>. The processor <NUM> may execute the set of instructions to perform one or more processes described herein. In some implementations, execution of the set of instructions, by one or more processors <NUM>, causes the one or more processors <NUM> and/or the device <NUM> to perform one or more processes described herein. In some implementations, hardwired circuitry may be used instead of or in combination with the instructions to perform one or more processes described herein.

The device <NUM> may include additional components, fewer components, different components, or differently arranged components than those shown in <FIG>. Additionally, or alternatively, a set of components (e.g., one or more components) of the device <NUM> may perform one or more functions described as being performed by another set of components of the device <NUM>.

<FIG> is a diagram of example components of a device <NUM>. The device <NUM> may correspond to the source device <NUM>, the destination device <NUM>, the network device <NUM>, and/or the like. In some implementations, the source device <NUM>, the destination device <NUM>, the network device <NUM>, and/or the like may include one or more devices <NUM> and/or one or more components of the device <NUM>. As shown in <FIG>, device <NUM> may include one or more input components <NUM>-<NUM> through <NUM>-B (B ≥ <NUM>) (hereinafter referred to collectively as input components <NUM>, and individually as the input component <NUM>), a switching component <NUM>, one or more output components <NUM>-<NUM> through <NUM>-C (C ≥ <NUM>) (hereinafter referred to collectively as output components <NUM>, and individually as the output component <NUM>), and a controller <NUM>.

The input component <NUM> may be one or more points of attachment for physical links and may be one or more points of entry for incoming traffic, such as packets. The input component <NUM> may process incoming traffic, such as by performing data link layer encapsulation or decapsulation. In some implementations, the input component <NUM> may transmit and/or receive packets. In some implementations, the input component <NUM> may include an input line card that includes one or more packet processing components (e.g., in the form of integrated circuits), such as one or more interface cards (IFCs), packet forwarding components, line card controller components, input ports, processors, memories, and/or input queues. In some implementations, the device <NUM> may include one or more input components <NUM>.

The switching component <NUM> may interconnect the input components <NUM> with the output components <NUM>. In some implementations, the switching component <NUM> may be implemented via one or more crossbars, via busses, and/or with shared memories. The shared memories may act as temporary buffers to store packets from the input components <NUM> before the packets are eventually scheduled for delivery to the output components <NUM>. In some implementations, the switching component <NUM> may enable the input components <NUM>, the output components <NUM>, and/or the controller <NUM> to communicate with one another.

The output component <NUM> may store packets and may schedule packets for transmission on output physical links. The output component <NUM> may support data link layer encapsulation or decapsulation, and/or a variety of higher-level protocols. In some implementations, the output component <NUM> may transmit packets and/or receive packets. In some implementations, the output component <NUM> may include an output line card that includes one or more packet processing components (e.g., in the form of integrated circuits), such as one or more IFCs, packet forwarding components, line card controller components, output ports, processors, memories, and/or output queues. In some implementations, the device <NUM> may include one or more output components <NUM>. In some implementations, the input component <NUM> and the output component <NUM> may be implemented by the same set of components (e.g., and input/output component may be a combination of the input component <NUM> and the output component <NUM>).

The controller <NUM> includes a processor in the form of, for example, a CPU, a GPU, an APU, a microprocessor, a microcontroller, a DSP, an FPGA, an ASIC, and/or another type of processor. In some implementations, the controller <NUM> may include one or more processors that can be programmed to perform a function.

In some implementations, the controller <NUM> may include a RAM, a ROM, and/or another type of dynamic or static storage device (e.g., a flash memory, a magnetic memory, an optical memory, etc.) that stores information and/or instructions for use by the controller <NUM>.

In some implementations, the controller <NUM> may communicate with other devices, networks, and/or systems connected to the device <NUM> to exchange information regarding network topology. The controller <NUM> may create routing tables based on the network topology information, may create forwarding tables based on the routing tables, and may forward the forwarding tables to the input components <NUM> and/or the output components <NUM>. The input components <NUM> and/or the output components <NUM> may use the forwarding tables to perform route lookups for incoming and/or outgoing packets.

The controller <NUM> may perform one or more processes described herein. The controller <NUM> may perform these processes in response to executing software instructions stored by a non-transitory computer-readable medium or transmitted via a transitory computer-readable medium. A non-transitory computer-readable medium is defined herein as a non-transitory memory device. A memory device includes memory space within a single physical storage device or memory space spread across multiple physical storage devices. Additionally, or alternatively, the techniques discussed herein may be realised at least in part by a computer readable communication medium that carries or communicates code in the form of instructions or data structures and that can be accessed, read, and/or executed by a machine, e.g. computer. In other words, any suitable computer readable medium may be used, which comprises instructions and which can for example be a transitory medium, such as a communication medium, or a non-transitory medium, such as a storage medium.

The software instructions may be read into a memory and/or storage component associated with the controller <NUM> from another computer-readable medium or from another device via a communication interface. When executed, software instructions stored in a memory and/or storage component associated with the controller <NUM> may cause the controller <NUM> to perform one or more processes described herein.

In practice, the device <NUM> may include additional components, fewer components, different components, or differently arranged components than those shown in <FIG>. Additionally, or alternatively, a set of components (e.g., one or more components) of the device <NUM> may perform one or more functions described as being performed by another set of components of the device <NUM>.

<FIG> is a flowchart of an example process <NUM> associated with a configuration of a network using a flex-algorithm routing mechanism. In some implementations, one or more process blocks of <FIG> may be performed by a network device (e.g., one or more network devices <NUM>). In some implementations, one or more process blocks of <FIG> may be performed by another device or a group of devices separate from or including the network device, such as a source device (e.g., the source device <NUM>) and/or a destination device (e.g., the destination device <NUM>). Additionally, or alternatively, one or more process blocks of <FIG> may be performed by one or more components of device <NUM>, such as the processor <NUM>, the memory <NUM>, the storage component <NUM>, the input component <NUM>, the output component <NUM>, and/or the communication component <NUM>.

As shown in <FIG>, process <NUM> may include receiving an advertisement from a second network device, wherein the advertisement is associated with indicating that the second network device is configured to use a particular flex-algorithm (block <NUM>). For example, the first network device may receive an advertisement from a second network device, as described above. In some implementations, the advertisement is associated with indicating that the second network device is configured to use a particular flex-algorithm. The first network device and/or the second network device may be included in a non-segment-routing network.

In some implementations, the first network device may provide a flex-algorithm definition to the second network device. The flex-algorithm definition may be associated with the particular flex-algorithm and the first network device may receive the advertisement based on providing the flex-algorithm definition to the second network device.

As further shown in <FIG>, process <NUM> may include identifying, in the advertisement, an address of the second network device (block <NUM>). For example, the first network device may identify, in the advertisement, an address of the second network device, as described above. The address may include a loopback address associated with the second network device.

As further shown in <FIG>, process <NUM> may include configuring a routing table of the first network device to indicate that the second network device is capable of receiving traffic associated with the particular flex-algorithm (block <NUM>). For example, the first network device may configure a routing table of the first network device to indicate that the second network device is capable of receiving traffic associated with the particular flex-algorithm, as described above.

As further shown in <FIG>, process <NUM> may include performing, using the routing table, an action associated with routing traffic associated with the particular flex-algorithm (block <NUM>). For example, the first network device may perform, using the routing table, an action associated with routing traffic associated with the particular flex-algorithm, as described above.

In some implementations, performing the action comprises the first network device transmitting, using the address, the traffic to the second network device based on at least one of a route path to the second network device having a least-cost according to the particular flex-algorithm, or the second network device being the only network device communicatively coupled to the first network device that is configured to use the particular flex-algorithm.

In some implementations, prior to performing the action, the first network device may determine a cost associated with routing the traffic to the second network device according to the flex-algorithm. The first network device may configure the routing table to indicate the cost in an entry that includes a mapping of the address. The action may be performed based on the cost.

In some implementations, the particular flex-algorithm is a first flex-algorithm and the address of the second network device is a first address. The first network device may receive another advertisement from the second network device. The other advertisement may be associated with indicating that the second network device is configured to support a second flex-algorithm. The first network device may identify, in the other advertisement, a second address (e.g., a second loopback address) of the second network device. The first network device may configure the routing table of the first network device to indicate that the second network device is capable of receiving traffic associated with the second flex-algorithm based on the second address. The first network device may perform, using the routing table, an action associated with routing the traffic associated with the second flex-algorithm.

<FIG> is a flowchart of an example process <NUM> associated with configuration of a network using a flex-algorithm. In some implementations, one or more process blocks of <FIG> may be performed by a network device (e.g., one or more network devices <NUM>). In some implementations, one or more process blocks of <FIG> may be performed by another device or a group of devices separate from or including the network device, such as a source device (e.g., the source device <NUM>) and/or a destination device (e.g., the destination device <NUM>). Additionally, or alternatively, one or more process blocks of <FIG> may be performed by one or more components of device <NUM>, such as processor <NUM>, memory <NUM>, storage component <NUM>, input component <NUM>, output component <NUM>, and/or communication component <NUM>.

As shown in <FIG>, process <NUM> may include receiving, via a non-segment-routing network, information associated with a flexible algorithm (block <NUM>). For example, the network device may receive, via a non-segment-routing network, information associated with a flexible algorithm, as described above. In some implementations, the information associated with the flexible algorithm may include a flexible algorithm definition associated with the flexible algorithm.

Alternatively, and/or additionally, the information associated with the flexible algorithm may include an identifier associated with the flexible algorithm, information identifying a metric associated with determining a least cost path for transmitting traffic associated with the flexible algorithm, information identifying a type of calculation associated with determining the least cost path, and/or information identifying a constraint associated with determining the least cost path. The metric may include an intermediate segment to intermediate segment metric, a traffic engineering metric, and/or a minimum unidirectional link delay metric. The type of calculation may include a shortest path first calculation and/or a strict shortest path first calculation.

As further shown in <FIG>, process <NUM> may include associating a loopback address with the flexible algorithm based on receiving the information associated with the flexible algorithm (block <NUM>). For example, the network device may associate a loopback address with the flexible algorithm based on receiving the information associated with the flexible algorithm, as described above.

As further shown in <FIG>, process <NUM> may include providing, to one or more other network devices included in the non-segment-routing network, information indicating that the loopback address is associated with the flexible algorithm (block <NUM>). For example, the network device may provide, to one or more other network devices included in the non-segment-routing network, information indicating that the loopback address is associated with the flexible algorithm, as described above.

As further shown in <FIG>, process <NUM> may include receiving network traffic associated with the flexible algorithm based on providing the information indicating that the loopback address is associated with the flexible algorithm to the one or more other network devices (block <NUM>). For example, the network device may receive network traffic associated with the flexible algorithm based on providing the information indicating that the loopback address is associated with the flexible algorithm to the one or more other network devices, as described above.

In some implementations, the network device may receive information associated with another flexible algorithm. The network device may associate another loopback address with the other flexible algorithm based on receiving the information associated with the other flexible algorithm. The network device may provide, to the one or more other network devices included in the non-segment-routing network, information indicating that the other loopback address is associated with the other flexible algorithm.

In some implementations, the network device may receive flexible algorithm information from the one or more other network devices. The flexible algorithm information may identify another flexible algorithm and another loopback address associated with another network device, of the one or more other network devices. The network device may calculate a least cost path associated with transmitting traffic to the other network device based on a metric, a type of calculation, and/or a constraint identified in a flex-algorithm definition associated with the other flexible algorithm. The traffic may be associated with the other flexible algorithm and the network device may transmit the traffic towards the other network device based on the least cost path.

Thus, in some implementations, a first network device may receive an advertisement from a second network device. The advertisement may be associated with indicating that the second network device is configured to support a particular flex-algorithm. The first network device may identify, in the advertisement, an address of the second network device. The first network device may configure a routing table of the first network device to indicate that the second network device is capable of receiving traffic associated with the particular flex-algorithm based on the address. The first network device may perform, using the routing table, an action associated with routing the traffic associated with the particular flex-algorithm.

As used herein, traffic or content may include a set of packets. A packet may refer to a communication structure for communicating information, such as a protocol data unit (PDU), a service data unit (SDU), a network packet, a datagram, a segment, a message, a block, a frame (e.g., an Ethernet frame), a portion of any of the above, and/or another type of formatted or unformatted unit of data capable of being transmitted via a network.

As an example, "at least one of: a, b, or c" is intended to cover a, b, c, a-b, a-c, b-c, and a-b-c, as well as any combination with multiple of the same item.

Claim 1:
A method comprising:
receiving, by a first network device, an advertisement from a second network device,
wherein the first network device and the second network device are included in a non-segment routing network, and
wherein the advertisement is associated with indicating that the second network device is configured to support a particular flex-algorithm;
identifying, by the first network device and in the advertisement, an address of the second network device;
configuring, by the first network device, a routing table of the first network device to indicate that the second network device is capable of receiving traffic associated with the particular flex-algorithm based on the address; and
performing, by the first network device and using the routing table, an action associated with routing the traffic associated with the particular flex-algorithm.