When you receive an incoming call to your phone number, your other telephones (cell, home phone, car phone) will ring as well and the first one answered will be connected to the caller. Basically the call will be routed to all phone sets, which you will list in simultaneous ring option.
Inter2fone has it Headquarters in Miami, FL USA and has regional offices in Equator (Southamerica), and Switzerland (Europe). Was inittialy formed like a division of FIX GROUP to attend VoIP services for the Latinamerican Market.