1. A method performed in a user equipment (UE) for data communication in a 3GPP network via an access point name (APN) capable of providing support for packet data network (PDN) connectivity, the method comprising the steps of:requesting dual stack PDN connectivity from a gateway, wherein the gateway is configured to support both Internet Protocol (IP) version 4 (IPv4) and IP version 6 (IPv6) and the gateway is further configured to use single address bearers only; and
in response to the request for dual stack PDN connectivity:
receiving a single IP address, wherein the received IP address is one of: i) an IPv4 address and ii) an IPv6 address; and
receiving, from the gateway configured to support both IPv4 and IPv6, a cause code indicating one of: i) that only PDN type IPv4 is allowed for the requested PDN connectivity and ii) that only PDN type IPv6 is allowed for the requested PDN connectivity;
wherein the UE responds to the cause code by refraining from requesting a second IP address in addition to the received single IP address.