domain, with wavelength routing and wavelength-selective switching technologies, protection capabilities, and OAM (Operation, Administration, and Maintenance). Solutions for high capacity links are also offered by wireless media. Traditional micro- wave frequencies have limited bandwidth, but higher bands (e.g. E-band, W-band, D-band) have enough spectrum SO that wireless links with 10G and even higher capacities are possible. Combining optical and wireless domains with IP services works very well as a net- working solution. In IP networking, a recent development has extended IP MPLS VPN (virtual private network) principles to Ethernet services with E-VPN (Ethernet VPN), bringing to users of Ethernet service capabilities from the IP domain like multi-homing and load balanc- ing. In another networking area, deterministic network behavior is progressing in IEEE (Institute of Electrical and Electronics Engineers) and IETF (Internet Engineering Task Force), with tools for covering new use cases, for example, in the industrial area and also in 5G low layer fronthaul. With cloud deployments, 5G Core and radio network functions are virtualized, and these functions may be located more freely than previously. Connectivity in the trans- port network must be flexible SO that these functions may be relocated dynamically, with the help of SDN (Software Defined Networking). This all makes the 5G transport network more heterogeneous and flexible, as the transport network should support not only the first phases of 5G, but also include capa- bilities to adapt to future needs and 5G use cases, as transport network redesigns are costly and time-consuming. Some building blocks here relate to having the following: 1. Physical media with adequate bandwidth for the links, in order to be able to increase capacity without excessive lead times 2. A networking connectivity model which is flexible and resilient in order to arrange connectivity between any locations as wished; and in order to support service avail- ability in midst of a fai