In general, techniques are described for extending Mobile User Plane-Gateway architecture Border Gateway Protocol (BGP) signaling to an integrated Access Network-User Plane (ANUP) function in mobile networks. In an example, a method comprises receiving, by a network system, a routing protocol message comprising second tunnel information for a packet data unit (PDU) session for a User Equipment (LTE) and comprising data indicating a routing instance or a UE address for the User Equipment; by the network system, based on matching the second tunnel information with first tunnel information sent or received on an interface with a mobile network control plane function, generating forwarding information to map the UE address to the PDU session or to map the PDU session to the routing instance; and based on the forwarding information, outputting, by the network system, a packet associated with the PDU session.