An apparatus for user plane function, UPF, allocation, wherein the UPF is configured to provide a Protocol Data Unit, PDU, connectivity service between a terminal device and a data network on a user plane, and wherein the allocation is based on control information associated with an individual logical PDU entity and defining: - priority information indicative of a priority of the PDU entity relative to other PDU entities; and - pre-emption information indicative of at least one of ∘ whether the PDU entity is capable of being pre-emptively allocated to a UPF over other PDU entities served by that UPF; and ∘ whether the PDU entity when served by a UPF is vulnerable to being re-allocated for pre-emptively allocating other PDU entities to that UPF; the apparatus being configured to: detect an event that requires UPF allocation to a first PDU entity; select a first UPF, wherein the first UPF is serving one or more second PDU entities; determine, for the selected UPF, insufficient resources for serving the first PDU entity; perform, responsive to determining the insufficient resources of the selected first UPF, an evaluation of: - first priority information associated with the first PDU entity relative to second priority information associated with the one or more second PDU entities; and - at least one of first pre-emption information associated with the first PDU entity and second pre-emption information associated with the one or more second PDU entities; and trigger, dependent on the result of the evaluation, allocation of the first PDU entity to either the first UPF or a second UPF. - priority information indicative of a priority of the PDU entity relative to other PDU entities; and - pre-emption information indicative of at least one of ∘ whether the PDU entity is capable of being pre-emptively allocated to a UPF over other PDU entities served by that UPF; and ∘ whether the PDU entity when served by a UPF is vulnerable to being re-allocated for pre-emptively allocating other PDU entities to that UPF; ∘ whether the PDU entity is capable of being pre-emptively allocated to a UPF over other PDU entities served by that UPF; and ∘ whether the PDU entity when served by a UPF is vulnerable to being re-allocated for pre-emptively allocating other PDU entities to that UPF; detect an event that requires UPF allocation to a first PDU entity; select a first UPF, wherein the first UPF is serving one or more second PDU entities; determine, for the selected UPF, insufficient resources for serving the first PDU entity; perform, responsive to determining the insufficient resources of the selected first UPF, an evaluation of: - first priority information associated with the first PDU entity relative to second priority information associated with the one or more second PDU entities; and - at least one of first pre-emption information associated with the first PDU entity and second pre-emption information associated with the one or more second PDU entities; and trigger, dependent on the result of the evaluation, allocation of the first PDU entity to either the first UPF or a second UPF. - first priority information associated with the first PDU entity relative to second priority information associated with the one or more second PDU entities; and - at least one of first pre-emption information associated with the first PDU entity and second pre-emption information associated with the one or more second PDU entities; and trigger, dependent on the result of the evaluation, allocation of the first PDU entity to either the first UPF or a second UPF.