Method to provide elasticity in transport network virtualisation

1. A method for providing support for elasticity in network virtualization of a heterogeneous, multi-domain network, the method comprising:

receiving, from a plurality of network domains in the hetergeneous, multi-domain network, information about elasticity capability of physical paths in the plurality of network domains, the elasticity capability comprising the ability of each one of the plurality of network domains to add or release physical resources to meet service requirements;

summarizing the physical paths in the plurality of network domains into at least one virtual link;

producing a topology of a virtual network overlaying the heterogeneous, multi-domain network by associating elasticity parameters with the at least one virtual link, wherein the elasticity parameters represent the elasticity capabilities of the physical paths.

2. The method as defined in claim 1 comprising transferring said topology of said virtual network to a Service Controller.

3. The method as defined in claim 1 , wherein the elasticity capability of said physical paths is received as information about elasticity capability of a plurality of physical links forming said physical paths.

4. The method as defined in claim 1 , wherein the information about elasticity capability of said physical paths is received as part of information about service network parameters.

5. The method as defined in claim 4 , wherein the service network parameters received from network domains include one or more of availability of resources, delay, resiliency or jitter.

6. The method as defined in claim 1 , wherein the elasticity parameters include one or more of: maximum elastic bandwidth with traffic interruption, maximum elastic bandwidth without traffic interruption and maximum elastic bandwidth with multipath routing.

7. The method as defined in claim 1 performed in a Transport Controller.

8. A Transport Controller for providing support for elasticity in network virtualization of a heterogeneous, multi-domain network, the Transport Controller comprising:

a processor; and

memory containing instructions executable by said processor to cause the Transport Controller to:

receive, from a plurality of network domains in the heterogeneous, multi-domain network, information about elasticity capability of physical paths in the plurality of network domains, the elasticity capability comprising the ability of each one of the plurality of network domains to add or release physical resources to meet service requirements;

summarize the physical paths in the plurality of network domains into at least one virtual link; and

produce a topology of a virtual network overlaying the heterogeneous, multi-domain network by associating elasticity parameters with the at least one virtual link, wherein the elasticity parameters represent the elasticity capabilities of the physical paths.

9. The Transport Controller according to claim 8 operative to transfer said topology of said virtual network to a Service Controller for use in computing an end-to-end virtual path across the virtual network.

10. The Transport Controller according to claim 8 operative to receive the elasticity capability of said physical paths as information about elasticity capability of a plurality of physical links forming said physical paths.

11. The Transport Controller according to claim 8 operative to receive the information about the elasticity capability of the physical paths as part of information about service network parameters.

12. The Transport Controller according to claim 8 wherein the service network parameters received from the plurality of network domains include one or more of availability of resources, delay, resiliency or jitter.

13. The Transport Controller according to claim 8 wherein the elasticity parameters include one or more of: maximum elastic bandwidth with traffic interruption, maximum elastic bandwidth without traffic interruption and maximum elastic bandwidth with multipath routing.

14. A Service Controller for use in routing a service through a heterogeneous, multi-domain network in response to a service request, the Service Controller comprising:

a processor; and

memory containing instructions executable by said processor to cause said Service Controller to:

receive from a Transport Controller a topology of a virtual network overlaying the heterogenous, multi-domain network, wherein the topology of the virtual network was produced by associating elasticity parameters with at least one virtual link, wherein the at least one virtual link have been created by summarizing physical paths and the elasticity parameters represent the elasticity capabilities of the physical paths, and wherein information about elasticity capability of physical paths in a plurality of network domains has been received by said Transport Controller from said network domains, the elasticity capability comprising the ability of each one of the plurality of network domains to add or release physical resources to meet service requirements; and

compute an end-to-end virtual path across the virtual network in response to the service request based on a Service Level Agreement associated with the service request and the elasticity parameters of the virtual links.

15. The Service Controller as defined in claim 14 , operative to receive the information about the elasticity capability of the physical paths as part of information about service network parameters.