The service offered by telephone companies allowing creating the telephone numbers on the same line where the existing number is. The call tone for every number will be different from another. There is also an opportunity to program a custom ring tone for the incoming call.
uVOIPit is a retail international VoIP service and wholesale VoIP termination business. It started in February 2010, and LLC licensed in April 2010. Website: http://www.uvoipit.com