Configurations
of GSM/VoIP networks allow the service providers to avoid the local Wired
Public Switched Network (PSTN) in communication with a GMS mobile handset. As a
result, the high rates charged by telephone companies are avoided.
The selective call acceptance allows controlling incoming calls by making a list of telephone numbers which you are ready to accept. But incoming calls from subscribers that are not listed are directed to the answering machine by which the caller is informed that you do not accept calls at the moment.