the msc vlr 3 4 one of the configurations that can be applied is that of changing the addressing plan by replacing plan e 214 with e 164 of the sccp protocol signalling connection and control part the aim of this is to avoid the mode of routing tracking messages of the hplmn 9 of its redirection system and to connect directly to the hlr 5 of the hplmn 9 in this way it is possible to connect to the hlr 5 and the authentication and tracking steps are performed the user then receives a mobile telephone offer and thus continuity of service in fig2 another embodiment of the invention is described it relates to a situation in which it is impossible to connect to the hplmn network and the authentication and tracking steps are not completed the buffer hlr 1 can authorise the connection of a mobile terminal 6 on the basis of the imei and imsi numbers recovered by the msc vlr 3 4 in this case the authentication phase becomes inexistent the msc vlr 3 4 requests tracking directly from the buffer hlr 1 in phase 10 the latter accepts the tracking with restriction of all services in phase 11 except reception of sms the buffer hlr 1 obtains the imei of the mobile terminal 6 in phase 12 either directly in the tracking request of the msc vlr 3 4 or by querying the msc vlr 3 4 with a suitable map protocol message such as u201c provide subscriber info u201d these imsi and.