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.
This is Helen Hu from China Skyline which in the field of VoIP products, GSM Modem, sim bank and wifi phone. And also deal in routes .Urgent need non cli 92 pak direct route who has voip gateway .