as it accommodates the co-location of CN functions at edge cloud facilities with the MEC applications, hence having 5G use cases fulfilled using the fourth generation (4G) technology. For example, the serving gateway (SGW) function can be distributed at the edge and enhanced with an IP-based interface, very similarly to the SGi interface of the packet data network gateway, which selectively breaks out the traffic that needs to remain local, i.e. associated to MEC applications as well as to the V2X AS. The described solution is named serving gateway-local breakout (SGW-LBO) [9]. Similarly to the uplink classifier, it also allows the operator to steer the traffic based on different parameters such as the access point name, user identities, the packet header's 5-tuple, and the differentiated services code point (DSCP), while supporting user mobility, charging, lawful interception, and session management operations, without requiring changes in the 3GPP standards. 13 5G Network Slicing for V2X Communications: Technologies and Enablers Transport and Tunneling Protocol for V2X Tunneling protocol design is of paramount importance to properly support network slices and provide V2X-based services. We detail the 3GPP architecture and illustrate the main interfaces (Figure 13.3) that have been disclosed by the recently published standard guide- lines. We then summarize the current General Packet Radio Service (GPRS) Tunneling Protocol (GTP) properties, while shedding light on the main novelties introduced by the Segment Routing IPv6 (SRv6) protocol in view of the supporting V2X slices. 13.5.1 GTP-U Encapsulation GTP is the current encapsulation process used in mobile networks, being also part of the 5G network specifications. In particular, as described in Section 13.3.2, the UE establishes a data session and gets assigned the corresponding UPF that is in charge of routing and for- warding traffic between UE and the data network (DN). User data traffic arrives from the gNB (or eNB) to the UPF by means of the N3 interface, w