Network risk is the risk that the network(s) needed for the private party to deliver the contracted services will be removed, not adequately maintained or otherwise changed - including being extended to include additional infrastructure or services not foreseen or anticipated at the date of the contract - in a way that either prevents or frustrates the delivery of the contracted services, affects the quality of the specified outputs or in some other way affects the viability of the project.
Interface risk is the risk that the method or standard of delivery of the contracted services will prevent or in some way frustrate the delivery of the core services or vice versa.