A Path Computation Entity, PCE, (218b, 218c) for processing a Path Computation Element Protocol, PCEP, request (237, 239, 244), comprising: a processor; and, a memory configured to store processor-executable instructions, wherein the processor interfaces with the memory to execute the processor-executable instructions, whereby the PCE is operable to: receive, from a foreign domain PCE, the PCEP request to at least calculate a path for a tunnel associated with a network service, wherein the PCEP request includes an endpoint object which includes a service related description characterizing a path tunnel endpoint that is not bound to resources in advance, and an Include Route Object, IRO, field which indicates one or more domains through which the tunnel will traverse to a physical endpoint of the network service; check the PCEP request to determine whether a destination for the tunnel associated with the network service is encoded in a form of the service related descriptor; based on the determination that the destination for the tunnel associated with the network service is encoded in a form of the service related descriptor, read the IRO field and determine whether all of the one or more domains are under control of an associated Multi-Domain Orchestrator, MDO, (218b, 218c); and, based on the determination that all of the one or more domains are not under control of the associated MDO, determine a next-hop PCE associated with one of the one or more domains, formulate a subsequent PCEP request to at least calculate the path for the tunnel associated with the network service, wherein the subsequent PCEP request includes the endpoint object which includes the service related description but not the identifier of the physical endpoint of the network service, and the IRO field which has been updated by the PCE and indicates the one or more domains through which the tunnel will traverse to the physical endpoint, and send the subsequent PCEP request to the next-hop PCE. a processor; and, a memory configured to store processor-executable instructions, wherein the processor interfaces with the memory to execute the processor-executable instructions, whereby the PCE is operable to: receive, from a foreign domain PCE, the PCEP request to at least calculate a path for a tunnel associated with a network service, wherein the PCEP request includes an endpoint object which includes a service related description characterizing a path tunnel endpoint that is not bound to resources in advance, and an Include Route Object, IRO, field which indicates one or more domains through which the tunnel will traverse to a physical endpoint of the network service; check the PCEP request to determine whether a destination for the tunnel associated with the network service is encoded in a form of the service related descriptor; based on the determination that the destination for the tunnel associated with the network service is encoded in a form of the service related descriptor, read the IRO field and determine whether all of the one or more domains are under control of an associated Multi-Domain Orchestrator, MDO, (218b, 218c); and, based on the determination that all of the one or more domains are not under control of the associated MDO, determine a next-hop PCE associated with one of the one or more domains, formulate a subsequent PCEP request to at least calculate the path for the tunnel associated with the network service, wherein the subsequent PCEP request includes the endpoint object which includes the service related description but not the identifier of the physical endpoint of the network service, and the IRO field which has been updated by the PCE and indicates the one or more domains through which the tunnel will traverse to the physical endpoint, and send the subsequent PCEP request to the next-hop PCE. receive, from a foreign domain PCE, the PCEP request to at least calculate a path for a tunnel associated with a network service, wherein the PCEP request includes an endpoint object which includes a service related description characterizing a path tunnel endpoint that is not bound to resources in advance, and an Include Route Object, IRO, field which indicates one or more domains through which the tunnel will traverse to a physical endpoint of the network service; check the PCEP request to determine whether a destination for the tunnel associated with the network service is encoded in a form of the service related descriptor; based on the determination that the destination for the tunnel associated with the network service is encoded in a form of the service related descriptor, read the IRO field and determine whether all of the one or more domains are under control of an associated Multi-Domain Orchestrator, MDO, (218b, 218c); and, based on the determination that all of the one or more domains are not under control of the associated MDO, determine a next-hop PCE associated with one of the one or more domains, formulate a subsequent PCEP request to at least calculate the path for the tunnel associated with the network service, wherein the subsequent PCEP request includes the endpoint object which includes the service related description but not the identifier of the physical endpoint of the network service, and the IRO field which has been updated by the PCE and indicates the one or more domains through which the tunnel will traverse to the physical endpoint, and send the subsequent PCEP request to the next-hop PCE.