The present document describes the Diameter-based interfaces between the V2X Control Function in the HPLMN and the V2X Control Function in the VPLMN (V6 interface). This specification defines the Diameter application for V6 reference points between the V2X Control Functions. The interactions between the V2X Control Functions are specified. The stage 2 description for V2X service features in EPS is specified in 3GPP TS 23.285 [2].