Techniques for wireless communications include operating first and second access networks to provide wireless service to wireless devices. The first and second access networks are associated with respective first and second gateways. The first gateway is operated to (1) receive a request for transferring wireless service of a wireless device from the second access network to the first access network and (2) send a message that includes key information to the second gateway based on the request. The second gateway is operated to (1) send session context information to the first gateway in response to the message and (2) forward a data packet associated with the wireless device to the first gateway. The forwarded data packet includes a packet data network identifier (PDN-ID) to identify a packet data network (PDN) associated with a downlink data packet.