A wireless device may transmit a session initiation protocol (SIP) REGISTER request to an internet protocol multimedia subsystem (IMS) network entity. The SIP REGISTER Request may comprise a first SIP header field. The first SIP header field may comprise one or more indicators for V2X capabilities of the wireless device. The wireless device may receive a SIP response from the IMS network entity. The SIP response may comprise the first SIP header field confirming the registration of the V2X capabilities. The wireless device may receive a second SIP request from the IMS network entity. The second SIP request may comprise a second SIP header field. The second SIP header field may comprise one or more indicators for V2X multicast service capabilities. The second SIP request may comprise one or more configuration parameters to receive packets via V2X broadcast and multicast bearers. The wireless device may transmit a second SIP response to the IMS network entity. The wireless device may receive packets via the V2X broadcast and multicast bearers. According to an embodiment, the SIP header field may comprise a SIP Contact header field.