Service scaling in communications

1. A method for downscaling a deep packet inspection service in a network apparatus, the method comprising:

receiving data flow in a gateway virtual machine of a virtual network element via a software defined networking switch;

keeping track of data flow and control flow and their state per subscriber;

transmitting, from a cluster controller of the virtual network element, scaling information to the gateway virtual machine, the scaling information including information on the cluster controller's decision to shut down a deep packet inspection virtual machine;

selecting, based on the cluster controller's decision, a new deep packet inspection virtual machine for the data flow;

informing the software defined networking switch on the selection of the new deep packet inspection virtual machine;

instructing the new deep packet inspection virtual machine to re-create a flow identification for the data flow to ensure deep packet inspection service continuity; and

forwarding a data packet to the new deep packet inspection virtual machine, wherein a metadata header is stripped off in the new deep packet inspection virtual machine before the data packet is analysed in the new deep packet inspection virtual machine and forwarded to the software defined networking switch,

wherein the metadata header includes earlier service identification of the data flow, and

wherein the metadata header triggers the new deep packet inspection virtual machine to re-create a new data flow based on the metadata header to ensure deep packet inspection service continuity.

2. A method according to claim 1 , wherein the data packet forwarded from the gateway virtual machine to the deep packet inspection virtual machine includes information regarding current service identification as additional metadata.

3. A method according to claim 2 , wherein said metadata is included in a proprietary header extension, additional tunnel header, or as standard metadata such as a network service header.

4. A method according to claim 1 , wherein the new deep packet inspection virtual machine is selected by means of a specific algorithm.

5. A method as claimed in claim 1 , wherein

the new deep packet inspection virtual machine for the data flow is selected based on receiving the cluster controller's decision to shut down a deep packet inspection virtual machine, the decision being based on monitoring resource usage levels of the deep packet inspection virtual machine.

6. A method as claimed in claim 1 , further comprising informing the software defined networking switch on the selection of the new deep packet inspection virtual machine via a software defined networking controller.

7. A method as claimed in claim 1 , wherein the data packet is forwarded to the new deep packet inspection virtual machine via the software defined networking switch.

8. An apparatus comprising at least one processor; and at least one memory including a computer program code, wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus to perform any of the method steps of claim 1 .

9. An apparatus comprising:

at least one processor; and

at least one memory including a computer program code,

wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus to:

receive a data packet which includes a metadata header, wherein the metadata header includes earlier service identification of a data flow;

when receiving the data packet with the metadata header, re-create a new data flow and a flow identification in an own database of the apparatus;

strip off the metadata header before the data packet is analysed; and

forward the data packet to a software defined networking switch.

10. A computer program product embodied on a non-transitory computer-readable medium, said product comprising executable code that when executed, causes execution of functions of a method according to claim 1 .