This is a method of providing a phone service to people over the Internet. This type of service moves the traditional phone switch off site and allows more than one company to use a particular switch.
“Call filter” allows blocking/unblocking the incoming calls as easy as to make filtration, it also journalizes all rejected calls. It is very convenient if you do not want to receive a call from some subscribers, when they will call you, “Call filter” will do so that your line is engaged.