Content for  TS 23.287  Word version:  18.4.0

A UE needs to discover the V2X Application Server(s), when V2X communication over Uu operation mode is used. The V2X Application Server address information may be configured on the UE or provisioned over N1 reference point, as specified in clause 5.1.3.1. When the configuration contains the FQDN(s), the UE shall perform DNS to resolve the address(es) of the V2X Application Server. The UE may use the configured V2X Application Server information only in the designated geographical area. When the UE changes serving PLMN or crosses configured geographic areas, it should perform address resolution again.

Multiple V2X Application Servers may be involved in the V2X communication, each providing particular V2X services and/or serving a particular geographical region. Therefore, the V2X Application Server address information as specified in clause 5.1.3.1 can contain multiple servers' information. When multiple V2X Application Servers are configured, the application layer will choose the proper V2X Application Server to use. When localized V2X Application Servers are deployed, Anycast may be used to conceal the server change from the UE. In this case, a FQDN is configured for a large region, e.g. the entire PLMN, and the UE only needs to resolve it once to an Anycast address. The UPF is responsible for routing the traffic to the appropriate local V2X Application Servers based on Anycast address.