Some telephones, depending on the brand and model, have the intercom function, which allows to begin communication by sending the signal. When the signal comes, the telephone set rings a signal different from the standard ring tone call. After that the telephone temporarily switches off from the telephone line and works as an intercom.
MySipProvider is an Italian SIP traffic provider. We provide Wholesale A-Z with CLI. Our main target is business customer. Our company running since 2010 with 300 customers and 80 vendors.