A method of Non-Access Stratum, NAS, signaling at a network node configured for operation in a communication network that includes a core network and a first access network, wherein the communication network is a Third Generation Partnership Project, 3GPP, network, the first access network is a 3GPP Radio Access Network, RAN, the core network is a 3GPP core network, and a second access network is a non-3GPP RAN that is directly or indirectly coupled to the 3GPP RAN or the 3GPP core network, said method comprising: conditionally selecting the second access network for exchanging NAS signaling between the communication network and a targeted wireless device, wherein the second access network is different from the first access network and the NAS signaling relates to mobility management or session management of the targeted wireless device with respect to the first access network; exchanging the NAS signaling with the targeted wireless device via the second access network, when the second access network is selected, wherein exchanging the NAS signaling with the targeted wireless device via the second access network comprises communicating with a NAS server in the communication network to obtain an IP address associated with the targeted wireless device, encapsulating first NAS signaling outgoing to the targeted wireless device into one or more outgoing IP packets addressed to the IP address and transmitting the one or more outgoing IP packets to the NAS server, for transport to an access point in the second access network that is communicatively linked to the targeted wireless device, wherein the NAS server maintains a mapping between an identity of the targeted wireless device and the IP address of the targeted wireless device in the second access network; and exchanging the NAS signaling with the targeted wireless device via the first access network, when the second access network is not selected. conditionally selecting the second access network for exchanging NAS signaling between the communication network and a targeted wireless device, wherein the second access network is different from the first access network and the NAS signaling relates to mobility management or session management of the targeted wireless device with respect to the first access network; exchanging the NAS signaling with the targeted wireless device via the second access network, when the second access network is selected, wherein exchanging the NAS signaling with the targeted wireless device via the second access network comprises communicating with a NAS server in the communication network to obtain an IP address associated with the targeted wireless device, encapsulating first NAS signaling outgoing to the targeted wireless device into one or more outgoing IP packets addressed to the IP address and transmitting the one or more outgoing IP packets to the NAS server, for transport to an access point in the second access network that is communicatively linked to the targeted wireless device, wherein the NAS server maintains a mapping between an identity of the targeted wireless device and the IP address of the targeted wireless device in the second access network; and exchanging the NAS signaling with the targeted wireless device via the first access network, when the second access network is not selected.