Make sure that your port numbers matches in:
[TOPAZ -> SETUP -> NETWORK/FRONT OFFICE]
TOPAZ NETWORK, port: 25000
PABX3 INTERFACE, port: 25001
[PABX3 -> OPTIONS -> NETWORK -> ]
Listen port, port: 25101
TOPAZ IP, port: 25000
The EricssonService must run on port 25001.
In C:\Program Files\Datatex\EricssonService\[EricssonService.ini]
LISTEN_PORT=25001 //Port that Topaz is sending to
Setup and info about service to bar extensions on a Ericsson BP250