Wu Chou, ; Li Li, : 'Methods and Infrastructure of Network-as-a-Service' (Telecommunications, 2017), 'Network as a Service for Next Generation Internet', Chap. 2, pp. 25-50, DOI: 10.1049/PBTE073E_ch2 IET Digital Library, https://digital-library.theiet.org/;jsessionid=vxv8qd9ce5k2.x-iet-live-01content/books/10.1049/pbte073e_ch2