1. A method comprising:receiving, from a user equipment (UE) by a network node in a primary network, a secondary Internet Protocol (IP) address for the UE, the secondary IP address being associated with a secondary network of the UE, each of the primary network and the secondary network supported by a different radio access technology;
establishing at least one tunnel between the primary network and the secondary network to bridge the network node and the UE via the secondary network, the at least one tunnel including a special bearer to carry control and data packets between the network node and a gateway to the primary network;
conveying, by the network node to the UE, (i) an identifier of at least one radio access bearer for use in identifying encapsulated packets communicated via the at least one tunnel, and (ii) an indication of which protocol layer will be producing data communicated via the at least one radio access bearer;
receiving, by the network node, a packet to be delivered to the UE on a radio access bearer split between the primary and secondary networks;
encapsulating the received packet according to a tunneling protocol for the at least one tunnel; and
forwarding the encapsulated packet from the network node to the secondary network through the at least one tunnel.