Network slicing for 5G allows mobile network operators (MNOs) to deploy multiple logical, self-contained networks on their physical infrastructure, orchestrated according to specific service requirements. The aim is to achieve end-to-end (E2E) network slices from the mobile edge through the mobile transport to the core network. The chapter introduces a new architecture for the network slicing system to implement E2E network slices. It also addresses the challenges and requirements for the management and orchestration (MANO) of network slices, considering architectural and topological use cases and potential configurations.