By using VoIP technology and PortaSwitch, Internet telephony service providers can truly make the world "flat" for their customers. It is possible to reach phone numbers in virtually any country in the world, and as easy to make a call to the opposite hemisphere as to your neighbor. ITSPs wishing to offer special pricing for calls made between IP phones connected to PortaSwitch (regardless of the actual phone number) can use the Voice On-Net feature. When enabled, all calls between IP phones will be rated according to the special destination VOICEONNET.
So if customer A has a US phone number assigned to him, and calls a phone number in India assigned to another customer in your system, customer A will not be charged the international rate for this call, but rather a special On-Net rate defined by you.