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.
Trade Me(Thailand) Co., Ltd. is a License holder company to operate VOIP in Thailand. We have VOIP operation license from Nation Telecommunication Commission of Thailand.