The WLAN-GW supports 3G/4G interworking based on a per-UE GTP tunnel from WLAN-GW to the mobile packet core (GGSN or P-GW). For more details on the GTP uplink setup, see the GTP section. The bridged Wi-Fi AP connectivity with the WLAN-GW can be WLAN-GW-based (soft-tunnel/l2-ap), or it can be a native Layer 2 (regular group-interface).