Patent Description:
A universal customer premise equipment (uCPE) can comprise software virtual network functions VNFs running on a standard operating system hosted on a server. A uCPE can support a multi-vendor and multi-component infrastructure. In a network infrastructure, there can be two basic use cases. In a data center cloud, the hardware resources are not constrained. In such an environment, it is straightforward to create a new service or virtual network function VNF in the background and then to switch over to the new service. However, in other basic use cases such as edge cloud, hardware resources are constrained so that when a VNF upgrade is performed or a VNF service within a VNF service chain is substituted by another VNF service, a service disruption occurs, i.e. the service is down. In a NFV service chain, the disruption time can be huge while performing operations such as VNF replacement or VNF software upgrade. During the disruption time, the VNF service chain implemented in the NFV network infrastructure cannot be operated or used.

<CIT> discloses a system, a method, and a computer program product for preserving service continuity in a Network Function Virtualization based (NFV-based) communication network.

<CIT> discloses a virtual network function (VNF) management system including a computer-executable set of instructions to deploy a VNF using one or more resources allocated for use by the VNF in which the one or more resources are allocated by communicating with a resource manager that manages the one or more resources.

<CIT> discloses a cloud oversubscription system that analyzes overloading of hosted virtual machines on an individual basis to detect a probability of overload of a host. Most particularly, the system relates to a cloud oversubscription system that includes a model that analyzes loading of hosted virtual machines, and a recommender that uses the model to identify an action to resolve or prevent an excessive overload condition.

<CIT> discloses techniques of managing oversubscription of network resources.

<CIT> discloses determining oversubscription of a first virtualized network function for enabling flow control.

Accordingly, it is an object of the present invention to provide a method for reducing service disruption times for a UCPE in a network functions virtualization, NFV, network infrastructure during a VNF upgrade or VNF replacement.

This object is achieved according to a first aspect by a computer-implemented method comprising the features of claim <NUM>.

The invention provides according to a first aspect a computer-implemented method for reducing service disruption times in a network functions virtualization, NFV, network infrastructure comprising at least one universal customer premise equipment, uCPE, having hardware resources used for running virtual network functions, VNFs, on virtual machines, VMs, wherein in response to a request for substituting an implemented virtual network function, VNF, linked to other virtual network functions, VNFs, in a VNF service chain by another substitution VNF, resource allocation ratios of available hardware resources of the universal customer premise equipment, uCPE, are automatically increased from a default value by oversubscription to provide the hardware resources required for the substitution VNF.

In a possible embodiment of the computer-implemented method according to the first aspect of the present invention, the hardware resources of the universal customer premise equipment, uCPE, to be provided for the substitution VNF comprise hardware disc resources, Random Access Memory, RAM, resources and/or processor resources.

In a possible embodiment of the computer-implemented method according to the first aspect of the present invention, the request for substituting the implemented VNF of the VNF service chain by the substitution VNF is provided by an application of a user equipment, UE, and supplied via the management, automation and orchestration, MANO, layer of the network function virtualization, NFV, network infrastructure to the universal customer premise equipment, uCPE.

In the present invention, the previously implemented VNF linked to the other VNFs in the VNF service chain is removed from the VNF service chain after the substitution VNF has been booted up at a determined boot-up time.

In a possible embodiment of the computer-implemented method according to the first aspect of the present invention, the spin-up time for spinning up the substitution VNF is automatically determined based on the historical usage data indicating usage of hardware resources of the universal customer premise equipment, uCPE, over time.

In the present invention, after removal of the previously implemented VNF from the VNF service chain, the resource allocation ratios of the hardware resources of the universal customer premise equipment, uCPE, are automatically adjusted back to the default values.

In a further possible embodiment of the computer-implemented method according to the first aspect of the present invention, the resource allocation ratios of available hardware resources are incremented until the required hardware resources are provided.

In a further possible embodiment of the computer-implemented method according to the first aspect of the present invention, the resource allocation ratios of the hard disk resources are incremented up to <NUM>.

In a further possible embodiment of the computer-implemented method according to the first aspect of the present invention, the resource allocation ratios of the RAM resources are incremented up to <NUM>.

In a further possible embodiment of the computer-implemented method according to the first aspect of the present invention, the resource allocation ratios of the available processor resources are incremented up to <NUM>.

The invention further provides according to a further aspect, as defined by independent claim <NUM>, a network functions virtualization, NFV, network infrastructure comprising at least one universal customer premise equipment, uCPE, having hardware resources used for running virtual network functions, VNFs, on virtual machines, VMs, wherein in response to a request for substituting an implemented virtual network function, VNF, linked to other virtual network functions, VNFs, in a VNF service chain by another substitution VNF, resource allocation ratios of available hardware resources of the universal customer premise equipment, uCPE, are automatically increased from a default value by oversubscription to provide the hardware resources required by the substitution VNF.

In a possible embodiment of the network functions virtualization, NFV, network infrastructure, the hardware resources of the at least one universal customer premise equipment, uCPE, to be provided for the substitution VNF comprise hard disk resources, Random Access Memory, RAM, resources and/or processor resources.

In a further possible embodiment of the network functions virtualization, NFV, network infrastructure, a request for substituting the implemented VNF of the VNF service chain by the substitution VNF is provided by an application of a user equipment, UE, and supplied via a management, automation and orchestration, MANO, layer of the network functions virtualization, NFV, network infrastructure to the universal customer premise equipment, uCPE.

In the present invention of the network functions virtualization, NFV, network infrastructure, the previously implemented VNF linked to the other VNFs in the VNF service chain is removed automatically from the VNF service chain after the substitution VNF has been booted up at a determined boot-up time.

In a further possible embodiment of the network functions virtualization, NFV, network infrastructure, the spin-up time for spinning up the substitution VNF is automatically determined based on historical usage data indicating usage of hardware resources of the universal customer premise equipment, uCPE, over time.

In the present invention of the network functions virtualization, NFV, network infrastructure, after removal of the previously implemented VNF from the VNF service chain, the resource allocation ratios of the hardware resources of the universal customer premise equipment, uCPE, are automatically adjusted back to the default values.

In a further possible embodiment of the network functions virtualization, NFV, network infrastructure, the resource allocation ratios of available hardware resources are automatically incremented until the required hardware resources are provided.

In a possible embodiment of the network functions virtualization, NFV, network infrastructure, the resource allocation ratios of the hard disc resources are incremented up to <NUM>.

In a further possible embodiment of the network functions virtualization, NFV, network infrastructure, the resource allocation ratios of the Random Access Memory, RAM, resources are incremented up to <NUM>.

In a still further possible embodiment of the network functions virtualization, NFV, network infrastructure, the resource allocation ratios of the processor resources are incremented up to <NUM>.

As can be seen in the sequence diagram of <FIG>, the network functions virtualization, NFV, network infrastructure <NUM> can comprise at least one universal customer premise equipment, uCPE, <NUM> having hardware resources used for running virtual network functions VNFs on virtual machines VMs. The universal customer premise equipment, uCPE, <NUM> comprises in the illustrated exemplary embodiment an edge device <NUM> with an implemented VNF service chain. The network functions virtualization, NFV, network infrastructure <NUM> comprises in the illustrated embodiment a management, automation and orchestration, MANO, layer <NUM> which can receive requests from a user equipment device <NUM>. In response to a request for substituting or upgrading an implemented virtual network function VNF linked to other virtual network functions VNFs in the VNF service chain, resource allocation ratios of available hardware resources in the universal customer premise equipment, uCPE, <NUM> can be automatically increased from a default value by oversubscription to provide the hardware resources required by the substitution VNF. The hardware resources of the universal customer premise equipment, uCPE, to be provided for the substitution VNF can comprise hardware disc resources, Random Access Memory, RAM, resources or processor resources, i.e. CPU resources. The request for substituting or upgrading an implemented NVF of the VNF service chain by a substitution VNF can be provided by an application of the user equipment <NUM> and supplied via the management, automation and orchestration, MANO, layer <NUM> of the network functions virtualization, NFV, network infrastructure <NUM> to the universal customer premise equipment, uCPE, <NUM>.

The previously implemented VNF linked to the other VNFs in the VNF service chain of the universal customer premise equipment, uCPE, <NUM> can be removed in a possible embodiment from the VNF service chain after the substitution VNF has been booted up at a determined boot-up time. The boot-up time for booting up the substitution VNF can be automatically determined based on historical usage data indicating usage of hardware resources of the universal customer premise equipment, uCPE, <NUM> over time. After removal of the previously implemented VNF from the VNF service chain, the resource allocation ratios of the hardware resources within the universal customer premise equipment, uCPE, <NUM> can be automatically adjusted back to the default values.

In the sequence diagram illustrated in <FIG>, an application executed on the user equipment <NUM> can generate a request for upgrading or replacing a virtual network function VNF-A within a VNF service chain implemented on the universal customer premise equipment, uCPE, <NUM>.

In the illustrated example of <FIG>, the management, automation and orchestration, MANO, layer <NUM> of the network functions virtualization, NFV, network infrastructure <NUM> sends an inquiry to the universal customer premise equipment, uCPE, <NUM> to get a disc utilization ratio, i.e. a resource allocation ratio of the hard disc resources of the uCPE <NUM>. In response to the inquiry, the management, automation and orchestration, MANO, layer <NUM> gets the disc utilization ratio. In the next step, the management, automation and orchestration, MANO, layer <NUM> can adjust the resource allocation ratios for different hardware resources of the uCPE <NUM>, i.e. for the processor resources, for the disc resources and memory resources based on a new VM flavor.

In the next step, the management, automation and orchestration, MANO, layer <NUM> can create the new VNF-A (version V2) according to the request with a new image in the same service with the same networking as also illustrated in <FIG>.

As soon as the new virtual network function VNF, i.e. the substitution VNF, is up the previously existing VNF-A (version V1) is removed from the VNF service chain.

Finally, the resource allocation ratios for the hardware resources are readjusted back to the original default values.

The computer-implemented method according to the present invention uses the virtualization concept of oversubscription for underlying hardware resources for splitting up redundant or additional VNFs in a resource-constrained environment. In a cloud computing environment, it is possible to overcommit virtual resources on network nodes, in particular on universal customer premise equipment, uCPE, nodes. The network can comprise interrelated components including control diverse, multi-vendor hardware pools of processing, storage and networking resources. This allows to increase the number of instances running on a computation node at the cost of reducing a performance of the respective instances. For instance, the processor resources may use a default CPU allocation ratio of <NUM>:<NUM>. The default CPU allocation ratio of <NUM>:<NUM> means that a scheduler can allocate up to <NUM> virtual cores per physical CPU core. For example, if a physical CPU core has <NUM> cores the scheduler can see <NUM> available virtual cores. For a typical flavor definition of <NUM> virtual cores per instance, this ratio can provide <NUM> instances on a physical processing node.

Similarly, a default RAM allocation ratio of <NUM>:<NUM> means that a scheduler allocates instances to a physical node as long as the total amount of RAM associated with the instances is less than <NUM> times the amount of RAM available on the physical node.

For example, if a physical computation node has <NUM> Gigabit of RAM, the scheduler allocates instances to that node until the sum of the RAM associated with the instances reaches <NUM> GB. This can be for example <NUM> instances in a case where each instance has <NUM> GB of RAM.

After the cloud resource allocation ratios have been changed, the new substitution VNF can be booted. In a memory overcommitment, there are multiple different ways including host swapping, memory ballooning or TPS.

The universal customer premise equipment, uCPE, <NUM> can implement a VNF service chain comprising virtual network functions VNFs. These virtual network functions VNFs can include different kinds of networking functions such as routing, switching, network address translation (NAT), access control (ACL), quality of service (QoS), load balancing (LB), security including virtual private networking (VPN) and/or performance monitoring. The network functions virtualization, NFV, network infrastructure <NUM> provides a computing environment for introduction of new networking techniques or functions.

The universal customer premise equipment, uCPE, <NUM> of the network functions virtualization, NFV, network infrastructure <NUM> may comprise a high performance virtual switch or virtual network interface for carrier Ethernet, IP, VXLAN, MPLS or hybrid WAN. Exemplary devices include an FSP <NUM> ProVMe, an FSB <NUM>-XG304u or an FSB <NUM>-XG118Pro. A FSB <NUM> ProVMe is a high performance server integrated with hardware-based forwarding, encryption and synchronization engines. The FSB <NUM>-XG304u comprises a flexible uCPE device featuring modules for LTE and VDSL connectivity as well as VNF hosting on a server. The FSB <NUM>-XG118Pro comprises a <NUM> Gigabit per second programmable cell site gateway featuring a hardware-based synchronization and a modular server.

<FIG>, <FIG> show a flowchart of a possible exemplary embodiment of a computer-implemented method according to an aspect of the present invention. After starting the process in step S0, in step S1 the actual disc available and disc available least is got from the uCPE <NUM>. Further, the resource allocation ratios are persisted. In step S2, it is checked whether the minimum disc needed is less than the disc available least received in step S1. If this is the case, a scheduler hint is passed with the received disc available least. Otherwise, it is checked in step S4, whether the minimum disc needed is less than the actual disc available. If this is the case, then a scheduler hint is passed with the actual disc available to override the default reserved disc total in step S5. Otherwise, in step S6, the configuration disc thin provisioned is set. Further, the disc allocation ratio is set in step S6 by <NUM> times.

In step S7, it is checked whether the minimum disc needed is less than the actual disc available. If this is the case, the process proceeds further with step S5. Otherwise, the service chain SC needs more resources and the process is terminated in step S8.

After having passed the scheduler hints in step S3, S5, one gets the free RAM MB from the cloud in step S9. In step S10, it is checked whether the free RAM MB is greater than the required RAM. If the free RAM MB is greater than the required RAM the free CPUs is got in step S11. In contrast, if the free RAM MB is not greater than the required RAM, the RAM allocation ratio is increased by <NUM> times in step S12. Following S12, memory host swapping is enabled in step S13. After this, in step S14, it is again checked whether the free RAM MB is greater than the required RAM. If this is the case one gets the free CPUs in step <NUM>. Otherwise, the service chain SC needs more resources and the process is terminated in step S8.

The process continues as illustrated in <FIG>. In step S15, it is checked whether the free CPUs exceeds the CPU resources needed for the VNF. If this is not the case the CPU allocation ratio can be increased by <NUM> times in a possible embodiment in step S16. If the free CPUs are more than the CPU required for the VNF, a cloud scheduler update/restart is performed in step S17 to reflect the changes. In the next step S18, a spin-up of the VNF utilizes a time when the computed resources utilized is least based on a historical data usage of the node. The spin-up time for spinning up the substitution VNF can automatically be determined based on the historical usage data indicating usage of different hardware resources of the universal customer premise equipment, uCPE, <NUM> over time. The spin-up of the replica new VNF with the same networking as the original previously VNF is performed in step S19.

In step S20, it is waited until the new substitution VNF has been spun up. In the next step S21, the previously implemented VNF is removed automatically from the service chain SC. After removal of the previously implemented VNF from the VNF service chain SC, the resource allocation ratios of the hardware resources of the universal customer premise equipment, uCPE, <NUM> are automatically adjusted in step S22 back to the default values. The service chain edit is completed in step S23. An operator can be notified by a message or an alarm after the service chain edit operation has been completed.

Historical data of the uCPE device resource usage can be stored in a possible embodiment in an orchestrator layer <NUM> of the network. An analytic engine of the orchestrator layer <NUM> can be used to identify a time of a day, when the uCPE device resource usage is minimum. The spin-up of the new substitution VNF is scheduled during a time of the day when the resource usage is minimum as determined with the help of the analytic engine.

<FIG> illustrates an example for possible resource consumption as observed by the orchestrator layer <NUM>. For a uCPE device <NUM>, the available CPU may be <NUM>, the available RAM can be <NUM> Gigabyte and the available storage disc can comprise <NUM> Gigabyte.

The initial allocation ratios can e.g. be a CPU allocation ratio = <NUM>, RAM allocation ratio = <NUM> and disc allocation ratio = <NUM>. In the example, the service chain SC implemented on the uCPE device <NUM> can comprise two virtual network functions VNFs, i.e. a Fortinet VNF and a Vyatta VNF. The Fortinet VNF comprises <NUM> CPU, <NUM> Gigabit RAM and <NUM> Gigabyte disk storage. The Vyatta VNF may comprise <NUM> vCPU, <NUM> Gigabit RAM and <NUM> Gigabyte disk storage.

Claim 1:
A computer-implemented method for reducing service disruption times in a network functions virtualization, NFV, network infrastructure (<NUM>) comprising at least one universal customer premise equipment, uCPE, (<NUM>) having constrained hardware resources used for running virtual network functions, VNFs, on virtual machines, VMs, characterized in that,
in response to a request for substituting an implemented virtual network function, VNF, linked to other virtual network functions, VNFs, in a VNF service chain (SC) by another substitution VNF, resource allocation ratios of available hardware resources of the universal customer premise equipment, uCPE, (<NUM>) are automatically increased (S6, S12, S16) from a default value by oversubscription to provide the hardware resources required by the substitution VNF,
the previously implemented VNF linked to the other VNFs in the VNF service chain (SC) is removed (S21) from the VNF service chain (SC) after the substitution VNF has been booted up at a determined boot-up time, and
after removal (S21) of the previously implemented VNF from the VNF service chain (SC), the resource allocation ratios of the hardware resources of the universal customer premise equipment, uCPE, (<NUM>) are automatically adjusted back (S22) to the default values.