IP core network comprising: - at least one router to an external data packet network and at least one switch connected to said at least one router, said at least one switch being configured to exchange with said router IP data packets without establishing a GTP tunnel, said at least one switch being connected to at least one base station of an access network and configured to exchange with said base station non-encapsulated IP data packets according to the GTP protocol; - a control device capable of controlling said at least one router and said at least one switch; and - a mobility management entity connected on the one hand by means of a communication interface with the control device and on the other hand to said at least one base station, said mobility management entity being configured to receive from said base station a message relating to a terminal and to transmit to said control device status information representative of a mobility and/or IP connectivity state of said terminal derived from the message; said control device comprising: - a communication module for communicating with said mobility management entity of the IP core network, capable of receiving from said entity status information representative of a mobility and/or IP connectivity state of said terminal; - a module for keeping up to date topology information (TOPO) representing connections that exist between said at least one router, said at least one switch, said at least one base station and terminals registered with the core network, said module being capable of updating at least a part of said topology information as a function of said status information; and - a control module of said at least one router and of said at least one switch, configured to define and update processing rules intended to be applied to data streams intended for said terminals registered with the core network, said processing rules being defined on the basis of said topology information kept up to date, said control device being configured to transmit said processing rules to said at least one router and/or to said at least one switch. - at least one router to an external data packet network and at least one switch connected to said at least one router, said at least one switch being configured to exchange with said router IP data packets without establishing a GTP tunnel, said at least one switch being connected to at least one base station of an access network and configured to exchange with said base station non-encapsulated IP data packets according to the GTP protocol; - a control device capable of controlling said at least one router and said at least one switch; and - a mobility management entity connected on the one hand by means of a communication interface with the control device and on the other hand to said at least one base station, said mobility management entity being configured to receive from said base station a message relating to a terminal and to transmit to said control device status information representative of a mobility and/or IP connectivity state of said terminal derived from the message; - a communication module for communicating with said mobility management entity of the IP core network, capable of receiving from said entity status information representative of a mobility and/or IP connectivity state of said terminal; - a module for keeping up to date topology information (TOPO) representing connections that exist between said at least one router, said at least one switch, said at least one base station and terminals registered with the core network, said module being capable of updating at least a part of said topology information as a function of said status information; and - a control module of said at least one router and of said at least one switch, configured to define and update processing rules intended to be applied to data streams intended for said terminals registered with the core network, said processing rules being defined on the basis of said topology information kept up to date,