An apparatus, comprising: storing means for storing data in at least one database, DB, of a shared data layer providing a data centric network architecture, wherein the data stored in the shared data layer is shared by a plurality of network entities, wherein the data comprises at least one of user subscription data or session data, wherein the network entities comprise one or more mobility management entities, mobility and session management entities, MSMs, service capability exposure functions SCEF, or gateways, means for downloading by a mobility management entity of a visited public land mobile network, the user subscription data from a home subscription server HSS, means for storing the downloaded user subscription data in the shared data layer of the visited public land mobile network, checking means for checking whether the user subscription data or session data is available in the shared data layer of the visited public land mobile network; and at least one of: when the user subscription data is available in the shared data layer of the visited public land mobile network, reducing means for reducing part of or all intra or inter-public land mobile network signaling between the network entities and the home subscription server HSS; when the session data is available in the shared data layer of the visited public land mobile network, reducing means for reducing part of or all intra or inter-public land mobile network signaling between the network entities. storing means for storing data in at least one database, DB, of a shared data layer providing a data centric network architecture, wherein the data stored in the shared data layer is shared by a plurality of network entities, wherein the data comprises at least one of user subscription data or session data, wherein the network entities comprise one or more mobility management entities, mobility and session management entities, MSMs, service capability exposure functions SCEF, or gateways, means for downloading by a mobility management entity of a visited public land mobile network, the user subscription data from a home subscription server HSS, means for storing the downloaded user subscription data in the shared data layer of the visited public land mobile network, checking means for checking whether the user subscription data or session data is available in the shared data layer of the visited public land mobile network; and at least one of: when the user subscription data is available in the shared data layer of the visited public land mobile network, reducing means for reducing part of or all intra or inter-public land mobile network signaling between the network entities and the home subscription server HSS; when the session data is available in the shared data layer of the visited public land mobile network, reducing means for reducing part of or all intra or inter-public land mobile network signaling between the network entities. when the user subscription data is available in the shared data layer of the visited public land mobile network, reducing means for reducing part of or all intra or inter-public land mobile network signaling between the network entities and the home subscription server HSS; when the session data is available in the shared data layer of the visited public land mobile network, reducing means for reducing part of or all intra or inter-public land mobile network signaling between the network entities.