a bsc rnc centre 18 connected to the sgsn node 14 and an msc centre 16 connected to the bsc rnc centre 18 the communication network 10 further comprises an smsc centre 26 connected to the msc centre 16 the communication network 10 further comprises an application server 24 connected to the smsc centre 26 and a telephone exchange 22 connected to the msc centre 16 and to the application server 24 the communication network 10 further comprises an configuration server 20 connected to the application server 24 the communication network further comprises an hlr database 30 connected to the application server 24 and to the sgsn node 14 finally the network 10 comprises two probes 28 1 28 2 in order to monitor and probe signal links these probes 28 1 28 2 are connected to the configuration server 20 several configuration servers 20 can be connected together although this is not shown in fig1 if information about a subscriber is not present in the centre to which the application makes its request the correct configuration server 20 can be found with the aid of ati the request is made from one configuration server to another using a new protocol fig2 shows a block diagram of a second embodiment of the communication network shown in fig1 similar components have been denoted in the communication network 40 using the same reference numbers as those used in fig1 these components will not be described further this network 40 further comprises an hlr database 30 connected to the application server 24 and to the sgsn node 14 as fig2 makes clear no probes are included in.