A method of selecting an end-to-end route within a network comprising a plurality of domains, the method comprising: for a required service, and for each of a plurality of physical paths (150, 151, 152) in at least one domain of the plurality of domains, setting a respective parameter value, wherein each parameter value is based on resources that are available for the required service, and said parameter value being dependent on a priority given to said required service, wherein each physical path is associated with: a service parameter that indicates resources on the physical path, and an elasticity parameter that indicates elastic resources on the physical path, and wherein the required service requests resources of the network to transport traffic; selecting the end-to-end route in the plurality of domains for the required service based on said parameter values of the at least one domain of the plurality of domains, wherein the end-to-end route comprises a virtual link in the at least one domain, and wherein the virtual link is represented by the plurality of physical paths (150, 151, 152); and in each domain including said virtual link of the end-to-end route, selecting, for said virtual link and for the required service, a physical path that has a minimum value of a sum of resources on the physical path and elastic resources available on the physical path, excepting resources already allocated to other services having a priority higher than or equal to said required service, wherein the sum of resources of the physical path exceeds the resources required for said required service, wherein the physical path in the domain is selected according to a service parameter and an elasticity parameter requested in the required service at the virtual link, wherein the elastic resources represent elasticity capability in a virtual network, and wherein the elasticity capability is an ability to provide resources that are dynamically enough to the required service, during lifetime of the required service. for a required service, and for each of a plurality of physical paths (150, 151, 152) in at least one domain of the plurality of domains, setting a respective parameter value, wherein each parameter value is based on resources that are available for the required service, and said parameter value being dependent on a priority given to said required service, wherein each physical path is associated with: a service parameter that indicates resources on the physical path, and an elasticity parameter that indicates elastic resources on the physical path, and wherein the required service requests resources of the network to transport traffic; selecting the end-to-end route in the plurality of domains for the required service based on said parameter values of the at least one domain of the plurality of domains, wherein the end-to-end route comprises a virtual link in the at least one domain, and wherein the virtual link is represented by the plurality of physical paths (150, 151, 152); and in each domain including said virtual link of the end-to-end route, selecting, for said virtual link and for the required service, a physical path that has a minimum value of a sum of resources on the physical path and elastic resources available on the physical path, excepting resources already allocated to other services having a priority higher than or equal to said required service, wherein the sum of resources of the physical path exceeds the resources required for said required service, wherein the physical path in the domain is selected according to a service parameter and an elasticity parameter requested in the required service at the virtual link, wherein the elastic resources represent elasticity capability in a virtual network, and wherein the elasticity capability is an ability to provide resources that are dynamically enough to the required service, during lifetime of the required service.