High availability for virtual network functions

1. A method comprising:

with a Virtual Network Function (VNF) manager, managing a VNF that includes a plurality of VNF components running on a plurality of virtual machines, the virtual machines running on a plurality of physical computing machines;

determining a first number of virtual machines equal to a highest number of virtual machines provided by a single one of a plurality of physical computing machines for the VNF;

with the VNF manager, causing a Network Function Virtualization Infrastructure (NFVI) to have a total number of virtual machines provisioned, the total number being equal to a second number of virtual machines capable of providing for a current demand for VNF components plus the first number of virtual machines equal to the highest number of virtual machines being provided by a single one of the plurality of physical computing machines; and

detecting a change in the highest number of virtual machines being provided by the single one of the set of physical computing machines and, in response, adjusting the total number of virtual machines provisioned.

2. The method of claim 1 , wherein the change is a decrease, and wherein adjusting the total number of virtual machines provisioned includes decommissioning at least one of the plurality of virtual machines.

3. The method of claim 1 , wherein the change is an increase, and wherein adjusting the total number of virtual machines provisioned includes causing an additional virtual machine to be provisioned.

4. The method of claim 1 , wherein adjusting the total number is further based on current utilization of a network associated with the VNF.

5. The method of claim 1 , wherein adjusting the total number is further based on utilization of processors of the plurality of physical computing machines.

6. The method of claim 1 , wherein adjusting the total number is further based on a number of subscribers currently using a telecommunication service associated with the VNF.

7. The method of claim 1 , wherein the total number of virtual machines uses an active/active model.

8. The method of claim 1 , wherein the additional number is subject to a set of constraints.

9. A system comprising:

a processor; and

a memory comprising machine readable instructions that when executed by the processor, cause the system to:

manage a plurality of Virtual Network Function (VNF) components for a VNF running on a plurality of physical computing machines;

determine a number of virtual machines capable of meeting current demand for the VNF;

determine an additional number of virtual machines equal to a highest number of virtual machines provided by a single one of a plurality of physical computing machines for the VNF;

cause a total number of virtual machines to be provisioned, the total number being equal to a sum of the of virtual machines capable of meeting current demand for the VNF and the additional number; and

detect a change in the highest number of virtual machines being provided by the single one of the plurality of physical computing machines and, in response, adjusting the total number of virtual machines provisioned.

10. The system of claim 9 , wherein to cause the total number of virtual machines to be provisioned, the system is further to add an additional virtual machine in response to the total number of virtual machines being greater than a current number of virtual machines.

11. The system of claim 9 , wherein to cause the total number of virtual machines to be provisioned, the system is further to decommission at least one of the virtual machines in response to the total number of virtual machines being less than a current number of virtual machines.

12. The system of claim 9 , wherein each of the total number of virtual machines is active.

13. The system of claim 9 , wherein to cause the total of virtual machines to be provisioned, the system is to send an instruction to a Network Function Virtualization Infrastructure (NFVI) manager, the instruction being to provision an additional virtual machine or decommission at least one virtual machine.

14. The system of claim 9 , wherein the system is further to adjust the total number based on an item selected from a list consisting of:

current utilization of a network associated with the VNF; and

utilization of processors of the plurality of physical computing machines that support the virtual machines.

15. The system of claim 9 , when the system is further to adjust the total number based on a number of subscribers currently using a telecommunication service associated with the VNF.

16. A method comprising:

with a Virtual Network Function (VNF) manager, causing a plurality of virtual machines to be provisioned on a set of physical machines;

with the VNF manager, causing the plurality of virtual machines to each run a VNF component of a VNF;

determining a number of virtual machines sufficient to provide for a current demand for telecommunication services provided by the VNF components;

causing an additional number of virtual machines to be provisioned based on the highest number of the plurality of virtual machines being supported by a single physical machine;

detect a change in the highest number of the plurality of virtual machines being supported by the single physical machine; and

further adjusting a total number virtual machines that are currently provisioned for the VNF based on a change in the highest number of the plurality of virtual machines being supported by the single physical machine.

17. The method of claim 16 , wherein the VNF comprises a Session Border Controller (SBC).

18. The method of claim 16 , wherein the total number of virtual machines use an item selected from a list consisting of: an active/active model and an active/standby model.