ILURE message if the reports cannot be generated. The resource status report is then transmitted periodically by the eNB entity by sending the RESOURCE STATUS UPDATE message. 2.4.3. X2 interface management The X2 interface is set up with the intention of exchanging the configuration data necessary for both eNB entities to function correctly. One of the eNB entities initiates the procedure by indication of the cells served in the X2 SETUP REQUEST message to a candidate eNB entity. Signaling Protocols The candidate eNB entity responds with the X2 SETUP RESPONSE message, also containing the list of serving cells. The information communicated may also include the list of neighboring cells and the number of antennas for each serving cell. The eNB entity may refuse the establishment of the X2 interface by sending the X2 SETUP FAILURE message in response. The X2 setup is followed by configuration updating of the eNB entity if the configuration of the eNB entity changes. The configuration update is initiated by the ENB CONFIGURATION UPDATE message. The remote eNB entity may respond positively with the CONFIGURATION UPDATE ACKNOWLEDGE message or negatively with the ENB CONFIGURATION UPDATE FAILURE message. The reset of the X2 interface is intended to align the resources of the eNB entities in the case of an unexpected breakdown. The procedure is initiated by the RESET REQUEST message. The receiving eNB entity responds with the RESET RESPONSE message. The procedure does not affect the data exchanged during the X2 setup or the configuration update of the eNB entity. 2.5. GTPv2-C protocol GTP-U (GPRS Tunnel Protocol User) tunnels are used between two entities of the EPS network. Such tunnels enable the traffic data to be compartmentalized. GTP-U traffic tunnels are constructed on the S1-U, S5 and X2 interfaces. The tunnel is identified by the TEID parameter, the IP addresses and the UDP port numbers. The entity receiving the traffic or signaling data determines the value of the TEID parameter which the sending entity has to 