e specific cases, cross-bordering scenarios), where multiple administrative domains (and, in turn, multiple UPFs) are involved while providing V2X services to the same vehicles. 13.5.3 Scalability and Flexibility in SRv6 SRv6 better supports source routing for TE without incurring the heavy workload of states and signaling in the nodes by means of IDs, such as Multiprotocol Label Switching (MPLS) labels or IPv6 addresses. In contrast, GTP is mainly coupling the mobile infrastructure to the underlying transport network, representing a threat to the status quo as it brings single-vendor monolithic mobile network implementations. Adopting SRv6 in V2X-supported mobile infrastructures may bring an added value, as the operator may employ the same Layer-3 virtual private network (VPN) techniques that are used for managing and delivering enterprise services, which can be further improved in 5G fixed-mobile convergence (FMC). In addition, SRv6 boils down the complexity by reducing protocol overheads and removing the need for the UPF to keep states. This brings a big advantage in terms of scalability. SRv6 also allows efficient service level agreement (SLA)-enabled multicast content injection (suitable for specific V2X use cases) by means of the standard unicast core with the so-called "spray" method. On the other hand, SRv6 will show its drawbacks when dealing with legacy suppliers, as a packet processing engine should continually dig deeply into the IPv6 header, espe- cially when a big flow of data traffic arrives due to the high mobility in V2X scenarios. Essentially, SRV6 may require a programmable software data plane to be effectively imple- mented, UPF as fully virtualized NF, and specialized data plane acceleration solutions to continuously meet deep packet inspection requirements. Given the extent of advantages, the main technology limitations, and the recently started study item from 3GPP (3GPP TR 29.892, 2019), SRv6 might become the right candidate for updating the UP protocol while supporting upcoming stringent 