t routing Source routing paradigm, MPLS or IPv6 based Software defined networking, central control of network flows IPsec 3GPP selected technology for cryptographic protection on network domain MACSEC Link layer (MAC) security, complementing IPsec 9 Transport Segment routing is source routing, where the list of intermediate nodes to be visited is given as a segment list [13]. The segment list can be populated by, for example, by SDN control/network management, or by a path computation element. Segments are identi- fied by MPLS labels or by IPv6 addresses. Segment routing can be used, for example, as a form of traffic engineering or to realize service function chaining. Native Ethernet bridging best suits limited LANs. If no IP service is possible, an alter- native to native bridging is to have the flows programmed by an SDN controller. The Time-Sensitive Networking (TSN) task group is discussed in Section 9.5. The IP security suite of protocols [14-16] is for cryptographically securing the network domain interfaces of 5G, consisting of services for data origin authentication, integrity protection, encryption, and anti-replay protection. For IPsec, both tunnel mode and transport mode are referred to by 3GPP, as well as addition of DTLS (Datagram Transport Layer Security) for the Stream Control Transmission Protocol (SCTP)-based control plane [17]. MACSEC is a link layer security service which can complement IPsec with solutions that scale with the port count. With time, cryptographic algorithms that were previously considered safe may become breakable, which is why it is essential to keep the algorithms up to date with the latest standard. SDN and the concept of centralized control applies not only to switches but also to network nodes in general: optical elements and devices, switches, wireless transmission products, MPLS and IP routers, cloud infrastructure/data centers, and site solutions. This allows the possibility of controlling heterogeneous network layers and nodes uni- fying the operation, with SDN contro