A method for providing a network slice in a communication network performed by a slice creating and management entity, SCME, the network slice being configured for use by one or more customers, the method comprising: • receiving an indication of a set of requirements to be satisfied by the communication network for the one or more customers (step 1302); • selecting a network slice format from a set of predetermined network slice formats based on the set of requirements, and selecting the network slice according to the selected network slice format, wherein each of the predetermined network slice formats specifies a predetermined set of parameters; • transmitting instructions to a node in the communication network to allocate resources to the network slice (step 1308), characterized in that each of the plurality of network slice formats includes a different respective combination of unspecified parameters and specified parameters, the unspecified parameters and the specified parameters selected from a set of potential parameters, wherein the set of potential parameters includes: a virtual network graph structure; service-specific function elements to be instantiated; placement of service-specific function elements to be instantiated; forwarding rules of network nodes involved in the network slice; a service-specific data plane protocol to be used in the network slice; a customized protocol stack to be used in the network slice; and a virtual network physical topology to be used by the network slice, the method further comprising: • selecting and assigning values to the specified parameters of the selected network slice based on the set of requirements, and assigning, prior to an instantiation of the network slice, values to the unspecified parameters of the selected network slice based on the set of requirements. • receiving an indication of a set of requirements to be satisfied by the communication network for the one or more customers (step 1302); • selecting a network slice format from a set of predetermined network slice formats based on the set of requirements, and selecting the network slice according to the selected network slice format, wherein each of the predetermined network slice formats specifies a predetermined set of parameters; • transmitting instructions to a node in the communication network to allocate resources to the network slice (step 1308), each of the plurality of network slice formats includes a different respective combination of unspecified parameters and specified parameters, the unspecified parameters and the specified parameters selected from a set of potential parameters, wherein the set of potential parameters includes: a virtual network graph structure; service-specific function elements to be instantiated; placement of service-specific function elements to be instantiated; forwarding rules of network nodes involved in the network slice; a service-specific data plane protocol to be used in the network slice; a customized protocol stack to be used in the network slice; and a virtual network physical topology to be used by the network slice, the method further comprising: • selecting and assigning values to the specified parameters of the selected network slice based on the set of requirements, and assigning, prior to an instantiation of the network slice, values to the unspecified parameters of the selected network slice based on the set of requirements. a virtual network graph structure; service-specific function elements to be instantiated; placement of service-specific function elements to be instantiated; forwarding rules of network nodes involved in the network slice; a service-specific data plane protocol to be used in the network slice; a customized protocol stack to be used in the network slice; and a virtual network physical topology to be used by the network slice, the method further comprising: • selecting and assigning values to the specified parameters of the selected network slice based on the set of requirements, and assigning, prior to an instantiation of the network slice, values to the unspecified parameters of the selected network slice based on the set of requirements. • selecting and assigning values to the specified parameters of the selected network slice based on the set of requirements, and assigning, prior to an instantiation of the network slice, values to the unspecified parameters of the selected network slice based on the set of requirements.