There is provided mechanisms for communicating non-IP data over a PDN of PDN type IPv4, IPv6, or IPv4IPv6. A method is performed by a core network gateway node. The method comprises communicating IP packets over a packet data network of PDN type IPv4, IPv6, or IPv4IPv6 with an application server, the IP packets comprising an IP header and being addressed to a wireless device. The method comprises communicating header-less payload packets over the packet data network with the wireless device. The header- less payload packets correspond to the IP packets having the IP header removed and represent the non-IP data.